If you're thinking of buying the PC version of Left 4 Dead, you might want to look into purchasing the new Valve Complete Pack off Steam. In addition to L4D, the $100 package comes with both Half-Life games and a slew of additional content for each.

The Complete Pack includes all the expansion packs for Half-Life and Half-Life 2, Portal, and both the classic and Source versions of Team Fortress, Day of Defeat, and Counter-Strike. Peggle Extreme and Ricochet, too. It's over twenty games in total. The product page mentions, for you penny-pinchers, that buying these games individually would cost $134.82 more. Calculating the total gameplay hours you could get from the pack would be a lot more difficult. Hell, some people are still playing the original Counter-Strike.

Those of you who bought the Half-Life 2: Orange Box already have the priciest stuff in this bundle but this seems like a great present for a PC gamer who somehow never played any of Valve's games (or just never purchased them). Left 4 Dead won't be available until November 18th but the rest of the pack will certainly tide you over until then (and then some).