Yoda, Mace, Obi-Wan, Anakin VS Darth Revan, Darth Malak, Darth Nihilus, Darth Sion
Sorry if this exact fight has been done before but I'm a noob to the forums and looking through ALL of the fights is just a little too much of a task right now.
Anyway, the fight is the four most powerful Jedi from the Clone Wars versus the four most powerful (known) Sith from the Old Republic. The fight is all out between sabers and Force skills and there are no restrictions save one. Nihilus' drain game is fun for all to be sure. And we could argue alllllll day about whether his opponents would be powerful enough to stop it or not. So for argument's sake I'm declaring right now that he can't use it. We don't know enough about it at all. Does it work on everyone except the Exile? Does it not work on the Exile because she was severed from the Force? One-shot fights are no fun anyway.
Okay, so you can have them fighting whoever you want to but I would assume Yoda would fight Nihilus, Mace would fight Revan, Obi-Wan would fight Malak, and Anakin would fight Sion. Just my opinion but you guys can do whatever you want to. Have fun XD
Oh and P.S. This is every one of them at their strongest. Jedi from ROTS...Revan and Malak from the end of KOTOR...Nihilus and Sion from the end of KOTOR II.