Who has the best overdrive in FFX? I think it's either kimahri's nova or tidus's blitz ace. I cant decide. If someone out there hasn't gotten blitz ace, you need to stop the line in the middle or tidus will fall on his head. Here's few tips on how to get some overdrives:

Tidus- keep doing the newest over drive till you have the new one. After a looooong time you should have all four.

Kimahri's coolest overdrive-nova- Use lancet on Omega weapon