Your thoughts on which Gundam throughout all the Mobile Suit Gundam Series is the boss of all...
How about the Devil Gundam from Mobile Fighter G Gundam? Yeah, I know it was eventually defeated but it took a whole mess of wacky Gundams and the power of love to beat it.
Now, I've only seen about 1/2 the Gundam series, so I am no authority and my memory is never too great, but until I see Victory, Turn-A, After War, Unicorn and Age not to mention all those movies and specials, that's the best I can offer.
Incidentally, Deathscythe Gundam from G. Wing is my personal favorite model. I don't think it's anywhere near the most powerful. I just like the look of it.