Soulcalibur IV

Just fight 100 times online. It doesn't matter if you win or lose the match and it doesn't matter if its a ranked or player match. You can check in battle records to see how many times you have fought online.

(Boosting Method):
Ok, just got this with my buddy. You're going to want to pick Shura, and then pick a map where you can easily ring out, we did the River one where you're on a small platform going down stream (yes, I forgot the name). Then start up the game (be sure it's a ranked match) and run at your buddy and push him to the edge the while sprinting at him and he's near the edge, press Y, or Y+B and you'll do an Animation Grab on him and throw him off the edge...

Average Round Time: 4.5 Seconds.
Average Match Time: Under 30 Seconds (Damn Cut Scenes.)

Do this method and you'll have this (and the Level 20) in the bag.

Do this in Player matches. Pick Astaroth. Then, have your boosting partner make a character with little defense against grapples. Just throw your opponent around with grapple.

Or you can use The Apprentice. Just have your back to the edge of the stage and have your opponent walk up to you. Grapple him/her and they'll be thrown out of the ring.

Rinse and repeat for 100 matches for you and your opponent.