Team Fortress 2 [Steam store page]
I wanted to love this game, but found it hard to get into because it requires team effort (mainly a healer at your back) or you die exceptionally fast. Unlike Unreal Tournament or Counter-Strike: Source where you can easily play a quick lone wolf match

This is a fun but easy Diablo style dungeon crawler. It features quick travel via portals and spells, as well as a pet to sell items while you continue killing. Additionally there is a shared chest to transfer valuable items between characters