You need to actually go and find out what this game is about.

That is exactly what L4D is not, good work =)

So not only did you decide which game was better before playing either of them, but you also decided without even understanding what one of the games was about.  Do you own a gaming PC?  Is it really any surprise that you find R2 to be "a much better game in every way"?   This is what people are talking about when they use the phrase "fanboy logic".  Can we just be reasonable?

Note how most of the PC users in this thread have said both games look awesome, and I agree completely both games are going to be huge titles and they're both going to be amazing in their own respect.  I will probably play both for those reasons alone.  I have a hard time believing that anyone who truly gave it full and fair consideration could come to any conclusion that has one of these games better than the other in every category. 

But hey, its your opinion, if you want to miss out on the game thats your call. Not my loss thankfully.

Weapons: So I went R2 for weapons because insomniac are awesome at weapons design and integration into their level designs. Also not helped by left 4 dead using regular human weapons (and what I feel is rather generic attacks for the zombies that I've seen/read about).

Enemies: I assume you mean enemy design (artistic style and what not) or else it'll fall under AI, that one goes to Resistance aswell. 200 ft enemy (not sure if it's exactly 200 but it's in the hundreds) and ability of insomniac to make use of the freedoms given by a "alien race" makes it seem like R2 will have more interesting enemies then Left4Dead (who are generic zombies aside from the few boss zombie types players control).

AI: left 4 dead easily. Any system that spawns enemies randomly and in different locations with each play through is genius. We've seen flanking tactics, incredibly accurate enemies, grenade throwers that would feel at home in the manning household, but to make it so that you never know when you'll be hit AND how (which boss you'll encounter) is awesome. Also Turtle Rock would have to be really good at making human and zombie bots for this game to be a huge success.

Art direction: like I said in enemies, it's alien race vs human/zombies. Turtle Rock studios is pretty restricted where as insomniac can do anything they want, it's freakin' aliens!

Replay Value: Random spawnings each game = Left4dead wins. R2 multiplayer would have to be ridiculously good and have CoD4 type RPG system (that has big incentives for playing the extra hour) if it were to win.

Graphics: R2, easily. You're talking about a game that throws wave after wave after wave of zombies at you and is online, no way Left4Dead will look as good as a game that throws you down linear paths with scripted sequences.

Sales: Tough call, but R2. It's basically a franchise now, with a high pedigree developer, with a well established following VS a new game, a relatively unknown developer and an unproven formula with so many variables that could go wrong (people wanting cutting edge graphics, AI not working perfectly, complete reliance on online for legs). Still it's 360 + PC VS PS3, so it's still a contest.

Overall: I went with resistance because even though Left4Dead won in the crucial areas for me (replay and AI = major part of gameplay) it didn't win by much, but where resistance 2 wins (graphics, art, enemy... design, weapons) it will dominate those areas compared to Left.

Weapons- Resistance 2: L4D will have some pretty generic guns since that is really the style of game, R2 being more futuristic I would expect to have something a little more interesting than the shotgun, uzi, pistol, etc...

Enemies - Left 4 Dead: I think this might be a close category for a lot of people but for me the reason I go with L4D here is the awesome Boss infected and the fact that you will get to play them!  This one is a close one though.

AI - Left 4 Dead: Hands down with what we know right now L4D is has the more interesting AI, its one of the major selling points about the game.  The entire idea that it monitors the stress levels of each player and attempts to give them a balanced experience without overload or boredom is just awesome, this could seriously be a new staple of zombie games and possibly even FPS games in general if they pull it off like they say they have.

Art Direction - Neither?:  In terms of art direction they are both pretty similar, and they both have some aspects I like and don't like.  Pretty much a tie on this one imo.

Replay value - Left 4 Dead: This one ties back in with the AI director and the fact that scenarios will be different every time and that you can literally play the exact same level 100 times and not know where the zombies are going to be or where they are going to come from.  Add in the boss infected side of things where the PCs are doing their best to outsmart you and I can see myself playing this game for several years.

Graphics - Resistance 2: Valve has never really gone for stunning visuals but instead focused on universal performance on a variety of machines.  Combine that with Insomniacs dedicated focus on making the game look awesome and I think it should be clear not only which one will look better but which one should look better as well.

Sales- No Idea:  We don't really have hard sales numbers for PC games anyways and I could easily see both games breaking 3 million units.

Overall- Left 4 Dead: Clearly for my taste I will like L4D more, but I certainly plan on playing both games because they both look awesome~

Looks like L4D is an early contender for most overrated game of the year.

If by "overrated" you meant "underrated," I'd agree.

Also, keep in mind just how different these 2 games are. Left 4 Dead is a multiplayer only game that will probably retail for $40. It's not supposed to have "kick-ass graphics" though it will definitely impress in various ways when the final version is released. It's the perfect co-op online shooter...it's the next Counter-Strike...it's the first cooperative zombie shooter...whatever you want to label it as...it's far from overrated.  Hell, Will Wright mentioned AI Directors as one of the more important moves in recent gaming history.  And if I trusted anyone to come out with a more sophisticated online FPS AI system, the makers of the CS: Source bot are already on their way.

Resistance 2 also has a lot going for it, it's made by one of the best console developers...I don't keep up the news for the game though so I won't try to talk about it.

Yeah, not sure where 'whatever' got L4D being overrated.

There is no comparison, Resistance 2 will be the best FPS of the year.

L4D is somethig new and therefore it can flop more easier, if its not good. R2... well... resistance 2 looks like err... cheap half life 2.

I got it from the people in this thread.  L4D may be a great game, but its a new IP that noone has ever played.  For everyone to say it will be better than R2 or GeoW2 is ridiculous at this point IMO.