Arkham City improves on nearly every aspect of Arkham Asylum. Lots of fun, bigger world to explore, and the combat is top-notch.

This is a hard, hard game, but playing with a bunch of friends is pretty awesome. Get it if you like very micromange-y RTS kinda things.

This game is free, so why not grab it? It's a fun little isometric co-operative shooter you can play with some friends as a quick distraction. There's cool techno-gadgetry and a few different roles you can fill to kill aliens and accomplish the mission.

The only annoying thing is the way the lobby behaves -- you will disconnect and reconnect after each lobby, which is... Odd. Still, not a bad way to spend 30 minutes.