So, what are some of the toughest battles you've come across, but you also won?

Some of mine are:

*Shinryuu - Final Fantasy V -- This one was pretty tough. I failed a couple times here, but then I discovered a certain way of beating him after a while of searching the web. Thanks to the YouTube LPer HCBailly for that.

*Ex-Death - Final Fantasy V -- There was one point in the final battle where he always got me. Every damn time until my 500th try. I don't remember how he always got me, but I know it came at a certain phase of the battle.

*Ultima Weapon - Final Fantasy IV: The After Years -- In the final chapter, you have the option of fighting the superboss Ultima Weapon. I failed many times until finally, I was able to survive long enough to take him down. I don't have any particular strategy to thank for that. That battle I feel I really just won with luck.

*Omega - Final Fantasy IV: The After Years -- I couldn't get him on my first playthrough. I was way too weak. My second playthough, I was stronger at this point. Yeah, not much to say here, except that I survived after a couple tries. Still never beat him in FFV.

There were a couple monsters in FFXII that COULD be listed here, but they weren't really so much hard. They just had tons and tons of HP and it took a long time to end the battle.