Halo: CE - Really fun game. The single player is good, but it doesn't finish as good as it starts. Of course, it suffers from the same problems all the Halos do. The levels drag on for a little too long, many corridors and rooms look very similar*, and the parts with the Flood are generally not as fun. The multiplayer is just great. The one problem is the pistol is really over-powered, especially in the more open levels.
Halo 2 - Best of the series, and my favorite FPS that isn't on the N64. Everything good about the first Halo was refined to near perfection in the second. I can't think of a level that I didn't really like, something I can't say for the other two games. Multiplayer is even better than before with the re-balanced weapons.
Halo 3 - A disappointing entry in the series. The new gameplay additions and new weapons didn't do anything for me. The level design for a few of the later levels is just bad. Multiplayer is still as great as it ever was, but since I don't like the new weapons, I don't like it as much.
*Not a problem with all levels, but there are times where you go through a corridor that looks just like the corridor before it, only to enter a room that looks just like the room before it.
I completely disagree on what you said about Halo 2.
I like Halo 2 but it's no where near on the same level as Halo CE and Halo 3 in terms of SP and MP IMO.
