Most of the people I see here seem to have some intense hatred for Infinity Ward and an intense love for Treyarch. Well, let's try and address this problem.
Infinity Ward started CoD. Without them, there would be no CoD. That should already stop you from hating them.
Infinity Ward created the first modern warfare CoD game. Not only was it a whole new setting, it also brought on the multiplayer everyone knows and loves today. Again, another thing to thank them for.
Everyone hates Infinity Ward because of MW2. MW2 is a great game. IT HAS ITS FLAWS. No game is perfect. People who say "but IW didn't release patches" well tell me, how can a company which has lost half its staff, and has no money, able to develop patches? How? Infinity Ward was dissolved by Activision due to legal reasons. Not because "MW2 sucked" or whatever other idiotic reasons there are floating about.
If you dislike Infinity Ward for the sole reason that they developed MW2, then it's evident you haven't played any of their other games. ALL of their games have been worth buying. It's not as easy to say that for Treyarch's games.