As a long-time Steam user on OSX (I have the TF2 earbuds to prove it,) the games available on OSX and Linux are a paltry offering (one of the top selling games right now on OSX is "Left 4 Dead 2" released in 2009.)
There are few top-tier games. Borderlands 2 is the only recent game that comes to mind. It became so discouraging that I built a PC gaming machine. I hope for a day where I can buy new games on an OSX or Linux machine, but I do not plan on holding my breath.
The part that kills me about Borderlands 2 on OSX is when they finally released it you can't play with your character from steam... you haven't to make a new one.
There are few top-tier games. Borderlands 2 is the only recent game that comes to mind. It became so discouraging that I built a PC gaming machine. I hope for a day where I can buy new games on an OSX or Linux machine, but I do not plan on holding my breath.