Focus Rifle - Combine the Sentinel beam from Halo 2 with a sniper scope, and BAM.
DMR - Like the BR, but with 15 single shots instead of 36 shots in three-round bursts. And also with slightly better accuracy (depending on mode of use).
M6G Magnum - The same pistol from Halo 3, but has ability to use a lower-powered scope and fire more quickly.
Needle Rifle - Like a needler, but bigger, headshot-capable, and the needles don't seek out.
Plasma Launcher - A weapon that shoots tracking plasma grenades that will stick to their target.
Grenade Launcher - Fires a single grenade, capable of an EMP burst which lowers shields and disables vehicles temporarily.
Plasma Repeater - Basically an oversized Plasma Rifle, but better fits the category of rifle than its smaller counterpart.
Concussion Rifle - The plasma equivalent of a Brute Shot. Shoots grenades that explode on contact at a rate of fire.
MA37 AR - The first variant of the MA5 assault rifle family. Pretty much the same thing as the Halo 3 MA5C assault rifle.