What other game do you know that provides constant updates - one every three weeks or so. New games to play without having to make another purchase - HL Deathmatch - Counterstrike Source - The Half Life Lost Level (coming soon) and Day of Defeat Source -Yeah it sucked for a minute when everyone and their mom was trying to validate HL2 on that first week of release but after that Steam has been great. I totally support Steam and I'm looking forward to new Half Life add ons and hopefully Half Life 3 sooner rather than later.
