L4D (and L4D2) is not a LIVE friendly game it requires so much TEAMWORK in any of the Advanced and Expert levels its hard to just drop inot a group of PUG players. I play on the PC where the community is HUGE with the mods, new maps, etc.. and for every 1 game I play with players who dont BUM FOOK everybody else (run ahead to get stuff, then cry nobody helped um when they are getting killed) i play 10 that are full of A$$hats. As for LIVE my very small interaction with it makes my PC l4D playtime seem like its full of wonderfull people. LIVE is really got a problem with griefes and just plain annoying players. Friends helps that.. but as a slightly older then average player most of my real life friends are to busy dealing with Ex wives, kids and never ending bills (play those games now!) so most of my online freinds are met there, and sadly one good game does not make a good player. I have Attempted LIVE a few times and while I cuss with the best of um, a 12 year old thinking FOOK is the best word to ever come out of his mouth gets old when its said 20-50 times per minute.. let alone when its directed at you (which I can honeslty say I take some pleasure in winding um up more if I can if it gets to annoying).
As for Shadowrun, I liked the idea (not a horrible translation from the game) but it was bogged down with far to many keys and somewhat laggy early days. I havent logged in fro.. a year or more.. maybe 2 years?