What free games do you play?

TF2, but i paid for it back in the day...

and City of Heroes, now that it's F2P, too bad most of my heroes/villians are locked since free members only get 4 slots a server... ugh

I play TF2, and then I occasionally play League of Legends. Either way, both of those games are good enough to warrant charging for, even if I do suck at LoL.

tf2, but i paid for it back in the day. i think i paid like $10 for it on a steam sale. 
 
i also play a few times war inc. battlezone. i haven't played it a while though.

Heroes of newerth. I like it, its as hard as dota and if you get 1700 points fast you are free of noobs.

Spelunky, Cave Story and Knytt Stories.

http://www.spelunkyworld.com/original.html

http://www.cavestory.org/downloads_game.php

http://nifflas.ni2.se/?page=Knytt+Stories

League of Legends has sucked up a huge amount of time, and I have yet to drop a cent into it.

LoL when it suits me

I've dove into some bad free games for the hell of it.

Anyone remember the brief run of Fishing Champ?

League of Legends. Probably a bit too much actually.

League of Legends and TF2, though I bought TF2 back in beta (primeval warrior badge aww yeah)

@benpicko: It's got memory leaks coming out the wazoo, so no.

I played the Shin Megami Tensei MMO. I have been told League of Legends is good.

TF2. The end.

Orbiter, free spaceflight sim

http://orbit.medphys.ucl.ac.uk/

And OpenTTD

http://www.openttd.org/en/

TF2 and Legal Legends.
 
Ironically I've probably spent more than $60 on both of them.

@Video_Game_King said:

The ones people have gifted to me.

This. I don't really play any of the free arcade games off of XBL or anything like that.

And getting new games as gifts always feels awesome :D