I almost 1cc'd metal slug 3 the other day, got to the section with the doors where you have to shoot the 3 dots before i messed up; had to continue like 3 times after that.
i'm pretty boss at streets of rage 2 and 3 as well, i can 1cc those with decent consistency
as for multiplayer stuff, my cousins and I go nuts for some War of the Monsters and Spawn: In the Demon's Hand. Spend hours rocking that noise.
...oh, and I'm pretty boss at elmo's number journey.