I think Baki wins with high difficulty, the guy by the end of the anime already mastered the most deadly techniques and power of the best fighters: he mastered the mach fist: multiple punches that break the sound barrier, cord cutting: A technique in which Baki can rip out a nerve connected to some part of the body thus making it useless (Take out the cord to your right eye, left arm, leg, ect.) he also face off against almost as many different styles as Ryu, the only difference is Baki incorporates them into his style. Pre-timeskip Baki fought and beat the Great Yasha ape in their second fight and withstood multiple hits from it beforehand, this thing was powerful enough to one-shot pretty much any other anime in the jungle like bears for example and knock down tree with a single blow. Not to mention fighting Yukiro who one-shotted a bear and stopped an earthquake with a punch.
I think the hadouken will be the main problem but I don't think Baki would be hit by it due to star-up time and I don't think it's a particularly fast move, at least not from what is shown in the videos. Even if the hadouken does hit Baki I don't think it's strong enough to one-shot him, at least not without the dark hadou, I mean we are talking about a guy who withstood sound waves ravishing the inside of his body and causing all the water inside him to vibrate violently twice. So being stronger than a guy who can bend steel and rip a deck of cards with his thumb as well as crush a coin with two fingers, faster than a guy who breaks the sound barrier, and more skilled than multiple martial artist, even beating one very skilled on without the use of his right arm and right eye.
VS yasha ape
VS. Pro boxing (Guy kncoked out a pack of wolves and moved so fast it was hard to even count his punches) and Kaoru, this really strong guy:
Using all the techniques from the fighters, including the mach fist
VS cord cutting
Defeats this guy with a perfect body in one punch
Lastly the little test of strength of the guy baki beat, Retsu
@jnw93: That's Shin Akuma. Ryu isn't on par with Shin Akuma only Evil Ryu is.
He could turn evil @ any time
but if we are talking about Ryu from the SF2 movie then id say Baki win instead, hes much more agile than ryu.
Although if ryu manages to get a haduken on him he could win.