On another site, there was a gent who had just recently gotten Halo CE to play on the xbox 360. He had a lot of questions. It reminded me of the fun I had (and frustration at first) playingthru that game. So I wrote down a few tips for him. I thought, as a blast from the past, I would blog my response. Sorry it's so long.
Scott : I have probably played thru Halo CE a 100 times on the original Xbox. I simply loved that game. What may be for some; several SPOILERS to follow.
You learn to how to get the Hunter to rush you, sidestep, and then shoot him in the back with the pistol. In the later part of the game, you can take them out with the sniper rifle. Or for a lot of fun, toy with them ( at a distance ), and then kill 'em with several salvos of the needler. You know that you are good , when you can take out a hunter with a pistol shot in the neck. Shooting them in the side just seems to make them madder. If you wound a Hunter enough, they will give you the bum's rush.
btw: You can pick up, and then throw ahead of you several weapons at a time, in order to have a cache of different weapons to use, and plenty of ammo. Repetitive, but very useful. This works for vehicles also. You will find that weapons (and vehicles used) that you have picked up and dropped stick around for quite awhile. If you have not picked them up and dropped them, they tend to disappear.
Elites do not like being hit with a charged shot from the laser pistol, and then one shot in the head from the regular pistol. The needler is great fun to use on elites also. Shooting grunts with pistol or rifle makes them drop sticky grenades. When you have a good defensive position, kill some grunts in the same general area, then wait for several elites, and throw a frag into the pile of stickies. If you are out of frags, just super needle an elite. His explosion will cause a secondary explosion of the stickies.
For the Flood, use the Melee on the infection (baby flood) or hose them down with the assault rifle or a grenade, pistol on the pregnant flood (or needle gun), and the shotgun reigns supreme on the Flood soldiers. Without the shotgun, you will be flood bar-b-que.
The pistol can be your best friend. It will easily take down elites with a few shots to the head, jackals with shots thru the notch in their shield or head shots, hunters, and banshees. Jackals can be dangerous, as they are they best shots in the game. It is great fun to sneak up on them and pistol whip 'em. The assault rifle, laser rifle, laser pistol, or sticky grenades will eventually take out the covenant tank, if you didn't bring a rocket launcher.
The Marines are basically canon fodder. Most of the time they act stupidly, and aren't very good shots. Once in a while, you will get a marine gunner who can hit almost everything he shoots at. I found it better to drive, as it is much easier to get "road kills". In the canyons, marines are worth more dead for their weapons you can pick up and stockpile. When you first use the covenant beam to enter the ship, and face elites and grunts coming at you from 4 different doors, the marines are worth their weight in gold.
By playing thru the game so many times, and changing my strategy, I found places and things I did not know I could go or could do. The AI for the covenant gets interesting, in that I found places where I had never seen covenant before, or they did something they never had before.
Learn the enemy spawn points. Don't be afraid to back track then, and use the environment. Learn which weapons to have on hand, for the upcoming fight. If you try to "run and gun" on Legendary, you will simply die, and never finish the game.
It really gets to be fun, when you get good enough that even on Legendary, you can play thru the game and leave no covenant or flood left alive to tell the tale. Sometimes I feel sorry for grunts, but the only good flood, is a dead flood.