Sephiroth vs Raziel. I think Solid Snake might go fairly far as well.
"Stephen Wolfram is the creator of Mathematica and is widely regarded as the most important innovator in scientific and technical computing today." - Stephen Wolfram
Just to inform everyone, make sure you look at the brackets before you choose who you think will be in the finals. There are some matchups that just are improbable of happening. Happy picking!
If anyone's ever played Tenchu they'd know how badass Rikimaru is. It's a tough battle between him and Snake. I'm not really sure who I'll choose, but I'm pretty sure Snake will win anyway since no one played Tenchu. Samus will surely defeat Turok and my prediction for the final battle is Samus vs. Snake.