Surprising small things
If it's possible Modern Warfare 2 took me by surprise.
For a bunch of reasons I just didn't have very high expectations for this game. The reviews bashed the single player, I wasn't the biggest fan of Infinity Ward's last offering and thought it to be greatly overrated.
The single player for this game turned out far better than I was expecting.
The story was crazy--but to be honest that's kind of fine by me. I kind of like that it's got that ridiculous quality that a lot of action games have about it. If you really thought Modern Warfare 1 had a great story then this may disappoint--I thought that game's story was kind of blah so the more absurd take on this stuff was more fun for me.
But what really works in the game's single player is that it actually has a lot of variety in the what you're doing and where you're doing it. You travel all over the world to several different countries and unlike the first game there's more than just the brown place and the gray place and the tan place. Crowded cities, Arctic Air bases, Central Asian Steppe, castles...yeah this game has that.
For multiplayer they added a pretty solid co-op mode you can play split screen or over the internet. I can't really speak to the online multiplayer because I live in South Korea at the moment and the Pacific Ocean makes my games really choppy.
The take away for me in Modern Warfare 2 is that they did everything a little bit better and it added up to a lot more fun for me.