I'm never going to be able to finish writing up the fight so I decided to just put in the results.
Superman vs. Goku
Superman has a wealth of Strength feats but his greatest strength (and perhaps most famous) is the strength to move the planet:
which has a mass of 6 X10^24 Kg. Using the formula 10^(S/10) kilograms this gives Superman a total bench press of around 67 Quintillion Tons. This is supported because after Superman sundipped for 15 minutes his strength multiplied by 3 which led to this feat:
200/3= 66.6 The feat is confirmed!
Now let's do Goku. DBZ unfortunatly dosen't show much in the way of Strength Feats near the end of the Manga. Some try to use the feat of Goku not being able to lift 40 Tons in Base as proof of his lack of strength however the feat is invalid because we don't know the gravity of the planet he was on. However DBZ does give one very good feat which we can scale off. SSJ3 Gotenks spikes Buu into the ground and this is the result:
He craters the Earth. and it a very deep crater as can be seen by the diameter of it and the slope. Now Gotenks, being a fusion, was beating Super Buu who is powerful then Fat Buu which should make him more powerful then Goku. HOWEVER Gotenks is mostly playing around here and so this feat should be considered a casual feat. This gives a good ballpark for Goku's strength.
Gotenks is about 44 inches (an average between Goten's height of 38 inches and Trunks' 50 inches). Thie radius of the hole is about 200X his height (8,800 In.) This means that the total area of the hole is 243,161,600 In. Squared. After converting this into kilograms and rounding up (due to it's casualness) I got a total of 10^16 kilograms which is about the estimated kilograms of the asteroid that wiped out the dinosaurs. Using the old formula 10^(S/10) the total Strength score was 160. So we have the Strength Scores:
250 vs. 160
Superman has endured being directly between the planets New Genesis and Apokalips as they crash into each other:
Both of which were massive. He has also tanked a Supernova:
But it left him uncouncious. So his durability must lie between them, Two Large planets and a Yellow Star. Our Sun (A Smallish-Average Yellow Star) has a mass of 2 X 10^30. Halving that I got the nice round number of 10^30 which gives the nice round number of 300. Since Superman can tank two massive planets collapsing on him and can survive a supernova while badly injured it seemed about right.
Now for Goku's Endurance. Now for Goku. Frieza survived (if not tanked) the explosion of Namek. And SSJ Goku was more powerful then Frieza.
Goku is clearly above Planetary in Durability. But where is he?
Going by this calc:
Namek is somewhere between 42.75X - 523.75X harder to bust then Earth. Averaging gives us 265X. If we assume the SSJ Goku of Buu Saga could tank the Planetary explosion without being reduced to a critical state like Frieza then we can use that to find Goku's durability. The Mulipliers for SSJ2 and SSJ3 gives a total of X8 that of SSJ.
265 X 8 = 2,120. So Goku has an estimated Durability of 2,120X that of Earth. This would gives him a durability just below Jupiter and an Endurance score of 265.
Endurance: 300 vs. 265
Superman is a skilled warrior having been trained by Mongul, Wildcat, and Wonder Woman. He is an expert at utilizing pressure points as a non-fatal way of defeating his enemy.
Superman's IQ on combat related matters was judged at Base Brilliant (120) which scored 24.
Goku, on the other hand, is a combat Genius! From a young age he has been able to invent martial arts on the fly based on animals. He was even able to copy his opponent's techniques just from seeing them.
His skill often manifests in his combination of abilities he possesses including one of his most famous manuevers where he is able to trick Cell and use his Kamehameha and Shukan Ido in unison to destroy Cell without harming the Earth.
Goku's IQ in combat was ranked at 300 which gives him a score of 60.
Skill: 24 vs. 60
Superman is a genius. His brain is a marvel of modern science. Batman has credited Superman's Brain as above his own:
So apparently if Superman had as much time to study as Batman he would have even more knowledge. However he already knows much, he has an understanding of Kryptonian sciences far advanced of ours. His general IQ was rated at Baseline Super-Genius (160) which gives him a score of 32.
Goku, on the other hand, is not very knowledgable. He has spent all his time perfecting his fighting and has never once attended school. He is naive and bleieves things despite them being completely irrational. He honestly believed that it was actually Mr. Satan's Ki bringing Kid Buu to his knees.
Still it's not that overt, he can still speak and perform complex actions perfectly fine. Overall his IQ was rated at 95, which gives him a score of 19.
Intelligence: 32 vs. 19
Superman has trained in the Kryptonian Martial Art Torquasm-Vo, an art specifically designed to increase the mental functions and increase his willpower. His willpower is enough to resist the abilities of the Cosmic Being Dominus who even complimented him on it:
Considering how Dominus is able to affect Celesial Bodies with his mind I calculated Superman's willpower as slightly more then the moon. This gave him a total of 229.
Goku has his own share of willpower feats, as a child he was able to resist the Bankoko Bikkuri Sho (English-Thunder Shock Suprise) which has defeated people with far more experience:
Goku at the end of the series has inertia equivlent to a planet and can survive being an attempt at being digest by Buu utilizing his willpower. I gave Goku the willpower of a planetoid at 226.
Both are incredibly devoted heroes and both have feats of Stamina and resisting mental abilities, however Superman's training at it gives him the slightest of edge.
Willpower: 229 vs. 226
Speed and Reflexes:
Superman is Faster then the Speed of Light. But how fast is he exactly? (For the record Combat Speed and Travel Speed are the same). Going by this calculation:
Jimmy signals Superman, who arrives a few pages later, stating he was near Vega when he received the signal:
These events happened pretty rapidly, but to be conservative I'll use a low-end of 10 minutes, and a high-end of 1 minute.
Distance from Earth to Vega = 25.04 light-years.
Crossing that in 10 minutes gives a speed of 1,316,102.4c.
Using 1 minute, that number is multiplied by 10, to 13,161,024c.
Taking the conservate esimate Superman's Fastest is 1.3 Million X FTL. This gives Superman a score of 149. As Superman dosen't have any reflex feats greater then that that is both his score for Speed and Reflexes
Now Assuming Goku's speed is similar to Gotenks's speed when circling the Earth (similar with the Strength feat). Here is the calc for it:
it's nine laps in 7 seconds. Each lap being approximately 3/2 times the circumference of the earth.
The circumference of the earth is : Vertical circumference: 40,000 km, horizontal circumference 40,076 km.
S = 7 × ³/₂ × E
E = (E_h + E_v)/2
E_h = 40,076,000 m
E_v = 40,000,000 m
t = 7 s
Since the orbits were spread spread out symmetrically the average circumference of the Earth, E, is the constant we're using.
v = s/t = 7 × ³/₂ × (40,076,000 +40,000,000)/2 = 420 × 10^6
Answer: 420 × 10^6 or 1.4c (1.4 × lightspeed).
If we assume Goku's speed is similar that gives him a score of 99
However Goku's Reflexes are notably better then his Speed. In the Frieza saga he was able to dodge exploding light
If we multiply the speed of Light by 10 to get Goku's speed to get his base reflexes and then multiply it by 400 to get his SSJ3 Reflexes (50 X 2 X 4) then Goku's end reflexes are 4,000c at the end of the series. This would give him a score of 124
Note about Shukan Ido: Some people believe that having Shukan Ido (Instant Transmission) means that Goku can move "instaneously" and is thus infinitly fast. This is flawed logic. If that was true they would use it to get everywhere. The thing about teleportation is even if it instant (which Shukan Ido is) you need to think to do it and with Shukan Ido you need to lock onto a Ki Signature and concentrate. Thus it is usually faster to just fly there and only faster to use it when it is a vast distance away AKA not practical for combat. Goku has only used it in combat twice, once against a stationary opponent (Cell) and once against a distracted opponent (Buu).
Reflexes: 149 vs. 124
Speed: 149 vs. 99
Superman's Main Energy Projection is his Heat Vision:
Superman's Heat Vision to destroy Planets and burns hotter then the Sun:
However it can be fired with incredible accuracy:
This gets Superman a score of 274.
Conversly Goku's Major Energy Projection is his Kamehameha which was enough to equal Vegeta's Galick Gun back in the Saiyan Saga. However while this dosen't make his Kamehameha Planetary this does:
But how powerful is the Kamehameha?
Buu was supposedly going to destroy the universe:
This does not make him a Universebuster though, as no time frame was given. However to destroy any signifigant part of the universe it is neccesary to destroy a star which means Goku should be able to destroy a star. This is supported by the fact that in the upcoming OVA/Movie DBZ: Clash of the Gods (which is actually canon as it was completely controlled by Akira Toriyama and is supposed to be the canon replacement for DBGT) Goku is supposedly able to create enough energy to destroy stars. This gets him a score of 335.
While Superman's Heat Vision is more precise and has more uses that will be covered later. In terms of sheer Energy Projection Goku has the edge.
Energy: 274 vs. 335
Superman's ability in Torquasm-Vo allows him to enter the Theta State. The Theta State allows Superman to reality-shift in the local area and gives a degree of mental control over the area due to his incredible mental discipline.
This regional control gives Superman a calculated score of 98.
Goku on the other hand has the ability to charge his Ki up to affect the local area either defensively
At full power Goku's aura affects as far as the Holy Sphere:
His aura was calculated at 279 which means he can affects Celestial Objects utilizing pure aura.
Aura: 98 vs. 279
Damage= Maximum Ability Damage
R= Maximum Ability Range
V= Number of Useful Abilities Controlled
C= Maximum Ability Charge-up Time (in seconds squared)
A= Ability Score
Superman: 248 + 243 + 130/3: 174
Maximum Ability Damage: Planetary (Heat Vision)
Maximum Ability Range: Jupiter Orbit (Heat Vision)
Maximum Ability Versitility: 13 Abilities (Heat Vision, Super Breath, Microscopic Vision, X-Ray Vision, Electro-Spectrum Vision, Super Hearing, Super-Smell, Torquasm-Rao, Orbital Piledriver, Sun-dipping, Eidactic Memory, Solar Regeneration, Tactile Telekinesis)
Maximum Charge-Up Time: 6 Seconds (Heat Vision)
Goku: 303 + 323 + 100/8: 91
Maximum Ability Damage: Stellar (Genki Dama)
Maximum Ability Range: Solar System (Genki Dama)
Maximum Ability Versitlity: 10 Abilities (Genki Dama, Shukan Ido, Dragon Fist, Kiai, Kaio Ken, Destructo Disk, Solar Flare, Telekinesis, Mimicry)
Maximum Charge-Up Time: 60 Seconds approximate (Genki Dama)
Total and Analysis:
Superman Total: 1,671
Goku Total: 1,649
The Winner by less then 25 points is Superman.
Analysis: The two were pretty evenly matched in stats. Goku's High Aura neutralized Superman's Speed Advantage. Goku's knowledge at combat was countered by Superman's scientific knowledge of general matter. Superman was Stronger and More Durable but Goku had more energy allowing to pick at Superman from range. It all came down to abilities.
And with abilities we saw that Superman just had a few more cards up his sleeve and his trumps abilities like Heat Vision were able to charge much faster then Gok'u s abilities whch were either slow to charge or could easily miss.
The winner by a nose is Superman.
I hope you liked it and as always I appreciate feedback as well as ideas about more battles you want to see.