Well, that's an iffy subject. They both have their strengths and weaknesses. According to what I've analized after spening almost my whole life hopped up on SF2 I learned that Ryu has a higher attack power then Ken but Ken is faster, Ryu does more damamge with a hadouken while Ken does more with a Shoryuken. And I think Ken does more damage with punches then Ryu while Ryu can do more damamge with Kicks then Ken.