Flamethrower, now that there are all those crawlers would feel so cool to set them all on fire 
Flamethrower. Most satisfying gun to get kills with. Awesome for infection games too.
Either the brute shot or sentinel beam.
I miss the Silenced SMG from ODST.
Scarab gun, definitely.
For me, it’s probably a tie between the needle rifle and the plasma launcher. They were both such fun weapons to use. I mean, who doesn’t enjoy sticking an enemy with a launcher then watching them squirm for the last seconds of their lives. The needle rifle (along with sticky grenades and evade) was also what made elite slayer my favorite playlist in reach.
smg and although i hardly used it in reach, the plasma rifle, its been in all the halos except this one!
Plasma Launcher, Grenade Launcher and the Flamethrower.
Brute plasma rifle
Sentinal beam (halo 3 version). So under appreciated, it’s like the Focus rifle but x100000 more awesome.
smg, the REAL carbine, this carbine is not worthy of being called a carbine
Reach DMR, I’m tired of people saying that their better when this new version literally does the work for you.
I miss the Halo 2 Rocket Launcher. Seriously, how did a weapon go from air and ground tracking to strictly air. Was not cost effective enough?
I miss the knifle…I mean Brute shot.
If I could only choose 1, then the Flame thrower. But if they could add the Sentinel Beam the Halo 3 version, that would be great. If they wanted to re-skin the sentinel beam and rename it as a new Forerunner weapon, that would be Ok too. Just as Long as it operated identically to the Halo 3 one.
Halo CE Magnum. I liked killing Hunters with two shots.
Dat Brute Shot.
Brute Shot. Blade on the bottom, multiple chain grenades on top. What more can you ask for?
Halo CE plasma rifle!! Why did Bungie and 343 think it had to be replaced??
Every thing previously mentioned?