Achievement exploit

Here's how to get lots of achievements in Left 4 Dead by cheating. http://woodio.net/index.php/gaming/4-gaming/27-left-4-dead-achievement-glitching-cheats.html

Left 4 Dead glitches and exploit list

Huge list of Left 4 Dead bugs that you can exploit here: http://woodio.net/index.php/gaming/4-gaming/22-huge-left-4-dead-bug-glitch-exploit-list.html