I can't decide which would be better to play on.  Voice chat seems like it will be pretty important in this game, and I don't have a mic for PC. But the PC will most likely have downloadable content. 

PC. Since Valve is primarily a PC developer. Also, I don't have a 360.

I'll probably get it on my xbox.

Xbox.. simply because my friends will get it on that and I prefer the integrated interface that Xbox Live gives

pc becuase the 360 doesn't get either of these.

free mods
free updates from valve

PC, because I don't have a 360, and because considering it's valve the PC version will be slightly better

PC at least for me anyways. Everything that comes out for it will be free(mods, extra levels, etc.) plus I feel that as far as FPS games go, there is better precision  and control with a mouse and keyboard. Though it depends on what you play games better with in the end with really. Plus, because it's a coop game, play on the system that most of your friends are on. It is better to play coop with people you know and trust instead of random strangers.(You never know who your going to get)

"PC. Since Valve is primarily a PC developer. Also, I don't have a 360."

Xbox 360 since my PC can't run many games made within the last 2 years.

The PC version will probably be better supported because it's Valve. Also, if TF2 is any indicator, there will be many more people playing it on PC.

I have no idea yet, I was thinking about buying it on Xbox 360 but then I noticed that the game will be so much better on P.C. due to mods and stuff.

Yeah, my PC can't run games so I'll get it on my 360.

both

PC!!!!!

It's a co-op game, so I'll probably get it for my 360, since that's where all of my friends are at.

PC.  Reason:  See TF2.

On the pc

"PC. Since Valve is primarily a PC developer. Also, I don't have a 360."

I'll be getting it on PC because nearly all the people I play with are on PC(since it's my main gaming machine), and the mod support community for this game will be massive, so I cannot wait for that aspect.

i would have gone with pc.. i have a gaming pc.. but not so mani awesome titles like 360.. wich i also have.. so i go with 360

PC FTW.

PC, because I don't have a 360 and don't want one :P

PC because you're not chained down by whatever Microsoft says unless you only play Games For Windows titles which have just recently become much more tolerable.

More of my friends will be getting the 360 version but I'm gonna get the PC one for the free updates.

PC, everyone listed the reasons above: Mods, Updates, Free stuff, etc.

The only situation in which I'd buy an FPS for the 360 is if it's not for the PC.

360, since the game will run bad on my PC because its old.

PC will probably be the best game because of controls and speed.
Valve has confirmed that zombies are much faster in the PC game.
However it depends where your friends are.

Have the system specs been released yet, and will it cost as much as a full fledged game or will it be $20 like TF2.

PC, if a shooter is multi-platform I will always get it on the PC.

360, i perfer a controller

if it runs on my Pc the the answer is obvious (pc), if not 360

"Have the system specs been released yet, and will it cost as much as a full fledged game or will it be $20 like TF2."

Mods = win :D I'm already in the orange map phase of a campaign.

Xbox, more epic games.

"Xbox, more epic games."

I'd mainly stay onto my 360 more than my PC even though this game looks perfect to play on PC. So... 360.

I'd rather pick it up for PC, I'm more comfortable playing with a mouse and keyboard when it comes to FPS games.

PC, for the reasons everyone else has stated above: Mods, better control, free updates from Valve, better community, etc.

Not to mention - I don't have a 360.

definately pc
But aside from that choice, isn't it like TF2 where valve updates/tweaks it's source engine every now and then?
Which, if so, i guess is pretty hard / impossible to do on a X360

(Don't own a 360 but just wondering...)

I would get it for PC, but it wouldn't look very good. I'm probably going to end up playing it on 360.

360 because, my PC probably won't run it and the 360 has Xbox Live

If my PC can run it, which I highly doubt, I'll get it for PC

If not, 360.

PC definitely because they do not support their 360 versions, so no new content and no bug fixes. I suggest getting a mic you can get decent mics for cheap now and the PC version gets mods, new maps and patches.

Probably both.  360 for playing with my Live buddies, PC for content updates & mouse control.

Anyone find it odd that if you purchase L4D PC version you can get free shipping today? Why not buy it from steam like everyone else? makes sense for the xbox version though - http://www.ebgames.com/gs/stopwatch/dailydeal.aspx

I'm getting this on the 360 since my friend is getting it on the 360... plus why waste the money I spent to play on XBL.

"It's a co-op game, so I'll probably get it for my 360, since that's where all of my friends are at.
"

Both

ill be getting it for the PC. The fast and frantic gameplay seems more suitable for keyboard and mouse.