Wow, some of the comments in this thread are laughable at best. Until you've played 2v2 team slayer on Halo 1 and have mastered nade points, map control and spawn traps, as well as gained a level 50 general status in halo 3, your logic as to which game is better from a competitive standpoint is flawed. From a competitive standpoint, Halo CE on Xbox LAN is HANDS DOWN far more superior to that of Halo 3 when looking at it from a perspective of individual contribution. With that said, let's analyze one of the more intelligent posts within this thread.
Weapons are inconsistent in Halo 3.
They are consistent, but the hit boxes are so much bigger than that of halo 1 that it makes it easier to get a kill.
Weapons are consistent in Halo 1.
Very true. There is only 1 shooting glitch in the game and that is when jumping and turning with the rocket in the air.
Control physics are choppy in Halo 3. Control physics are smooth in Halo 1.
Halo 3 has physics? The physics are so inferior to that of halo 1, that throwing a nade by a weapon has no effect of blowing it to a different location! Part of what made halo so great is the ability to blow power ups and weapons to different locations of the map as part of the game strategy.
Gameplay is slow paced in Halo 3. Gameplay is fast paced in Halo 1. Not true. A game of 2v2 TS in halo 1 lasts about the same as 2v2 in halo 3. Same with 4v4 TS.
Shots don't register in Halo 3. Shots register in Halo 1. Not true. In lan, both games register shots and there is a fair amount of skill in using the BR just as there is the pistol in halo 1.
There is a larger skill gap in Halo 1. There is a small skill gap in Halo 3.
Very true. If you take a two players that have been playing halo 1 for a year, and 2 players that have been playing halo 3 for a year, as a noob team playing either game for the first time, you are going to get more kills against the good players in halo 3 then you will in halo 1. In halo 3, the noobs will get 10-15 kills, but in halo 1 they will be lucky to get 2-5 kills.
There is greater weapon balance in Halo 1. There is terrible weapon balance in Halo 3.
Halo 1 is not a game of weapon balance. It is a game of power up control, map control, and predicting kills off the spawn. It is a superior game which doesn't require the need for weapon balance. Depending on the location of the map, the sniper, rocket, and pistol can all be equally powerful in halo 1.
The health system in Halo 1 worked well with the game. The health system in Halo 3 further slows down the pace of the game. Both health systems work well for each specific game. Halo 3 is a much more team oriented game, where the chance of surviving a 2 on 1 is very slim. In halo 1, you can rocket one guy, quickly switch weapons, and three shot kill the other guy with the pistol, or switch to the sniper and gain a single kill. I have survived far more 2 on 1's in halo CE than I ever have in Halo 3. This is true for all skill levels.
Melees require much more skill to effectivley use in Halo 1. In Halo 3, you can just lunge. Very true.
Taking both games into account, Halo CE is a far more enjoyable game from a competitive stand point. If you are a competitive player, you will enjoy Halo CE much more than Halo 3.