Surprised to see someone mention DD: Neon. I loved it but it seemed like I was the only one as most people just dunked on it when it was first released on the PS3. Fight N Rage is also a good one. I liked Raging Justice but it doesn't hold a candle to the other games you mentioned.
Fight N Rage and Double Dragon neon belong into this list.
How can you leave out fight N Rage that game is awesome.
Nobody mentioned Castle Crashers.. now thats bad
Guardian Heroes is only £1.69 on the Xbox store, just picked it up yesterday. It's still amazing.
Been playing 9 Monks of Shaolin, definitely deserves to be on this list