Guide to Unlockables

I was bored so i decided to make a Guide to Unlockables.
NOTE: Things that are too hard for me or too simple aren't listed here.

ACHIEVEMENTS:

Banshees, Fast And Low:
There are many places where this can be done, but the easiest place to do this is on Tip of the Spear, when you have to attack the Spire along with Jorge. All dead Marines in the area will have a Jet Pack near them. Grab one. A bit farther there will be a Banshee flying low all the time. Use your Jet Pack to board it.

Blaze of Glory, Firestarter, Lucky Me, Heat in the Pipe, Crowd Control and Game, Set Match:
Make a custom Firefight gametype where in all rounds all skulls except Yellow, Red and Blue are on, you are invincible, do extreme damage, bottomless clip, high speed, Legendary, strong custom loadouts and start playing.

If They Came To Hear Me Beg:
There are amny places where you can do this, but the easiest way is at the beginning of The Pillar Of Autumn. Look down at the Elite standing near the Truck, wait till he turns his back to you, engage Sprint and assasinate him.
IMPORTANT:
Disengage Sprint before you assasinate the Elite.
You have to hit him before you touch him.
It has to be the Elite near the truck, not the one at the right from the bridge.

Your Heresy Will Stay Your Feet:
Grab a PP and a DMR. Once you are almost near the location of the Zealot, start charging your PP. Shoot him with the overcharged bolt, swap to your DMR and blow his skull.

Two Corpses In One Grave:
On ONI: Sword Base, once you grab the Target Locator and you open the door, start charging your Target Locator on the Warthog instantly after it is destroyed. You might need to recharge the checkpoint.

NAMEPLATES:
Successfully complete the indicated task to unlock the corresponding nameplate for Multiplayer mode. To activate it, log into Bungie.net, select "Account", "Game Settings", then "Nameplates".

Assault Rifle: Played the Halo: Reach beta in May 2010.
Halo 2 Logo: Played Halo 2 on Xbox Live before it's shutdown on April 15, 2010.
Halo 3 Logo: Play any Campaign level in Halo 3 on Xbox Live.
Marathon Durandal Symbol: Have Marathon Durandal in your recently played games list, and login at Bungie.net.
MJOLNIR Mk VI Helmet: Unlock any four of the Halo PC, Halo 2, Halo 3, Halo 3: ODST, or Halo: Reach beta nameplates.
ODST logo: Play Halo 3: ODST on Xbox Live.
Halo: CE Logo: Register your Halo PC product code at Bungie.net.
The Septagon symbol: Join Bungie.net, and login with your Gamertag's email address.

AVATAR AWARDS:

Jun's Helmet: This was the first one i got. If you really can't get this done then go play Firefight and make yourself Invincible.

Kat's Helmet: This was the second one i got. The best playlist for this is Invasion. If an enemy and a teammate battle eachother, and the enemy wins, he will mostly be unshielded so you can easily finish him.

Emile's Helmet: The third one i got. When the new Infection playlist came out, i got it a Bulltrue in my first game.

Jorge's Helmet: The last one i got. This one is very hard but i got it when playing Infection on Pinnacle. I camped in the tower till i was Last Man Standing and 6 Zombies came up the stairs. I was able to get a Killtacular on the first 5 but the last one killed me. EDIT: I got a Killtrocity with a Magnum on Asylum when camping on the edge of the map and blasting all the Zombies coming for me.

Carter's Helmet: I am still trying to unlock it, but my friend has it already. All you have to do is play Winter Contingency on Legendary and try to skip the largest part. I tried it once but i got killed by a BOB armed with a Concussion Rifle.

ARMORY UNLOCKS:

Haunted Helmet:
After buying all other Helmets, this can be bought for 1 cR as an attachment for Pilot.

Ability to see UA/Chobham and Tactical/Trauma Kit:
Buy Tactical/Hard Case.

Collar/Breacher [R](Kat's arm):
First buy Collar/Breacher.

Military Police Base:
Complete Campaign on Normal and have at least 450 Halo Gamerpoints.

CQB Base: Complete Campaign on Heroic and have at least 900 Halo Gamerpoints.

UA/Base Security Chest: Have at least 1900 Halo Gamerscore and have the achievement Yes, Sensei for halo: Reach.

RANK LIST:

Private: 7,500 credits
Corporal: 10,000 credits (+2,500 credits)
Corporal Grade 1: 15,000 credits (+5,000 credits)
Sergeant: 20,000 credits (+5,000 credits)
Sergeant Grade 1: 26,250 credits (+6,250 credits)
Sergeant Grade 2: 32,500 credits (+6,250 credits)
Warrant Officer: 45,000 credits (+12,500 credits)
Warrant Officer Grade 1: 78,000 credits (+33,000 credits)
Warrant Officer Grade 2: 111,000 credits (+33,000 credits)
Warrant Officer Grade 3: 144,000 credits (+33000 credits)
Captain: 210,000 credits (+66,000 credits)
Captain Grade 1: 233,000 credits (+23,000 credits)
Captain Grade 2: 256,000 credits (+23,000 credits)
Captain Grade 3: 279,000 credits (+23,000 credits)
Major: 325,000 credits (+46,000 credits)
Major Grade 1: 350,000 credits (+25,000 credits)
Major Grade 2: 375,000 credits (+25,000 credits)
Major Grade 3: 400,000 credits (+25,000 credits)
Lt. Colonel: 450,000 credits (+50,000 credits)
Lt. Colonel Grade 1: 480,000 credits (+30,000 credits)
Lt. Colonel Grade 2: 510,000 credits (+30,000 credits)
Lt. Colonel Grade 3: 540,000 credits (+30,000 credits)
Commander: 600,000 credits (+60,000 credits)
Commander Grade 1: 650,000 credits (+50,000 credits)
Commander Grade 2: 700,000 credits (+50,000 credits)
Commander Grade 3: 750,000 (+50,000 credits)
Colonel: 850,000 credits (+100,000 credits)
Colonel Grade 1: 960,000 credits (+110,000 credits)
Colonel Grade 2: 1,070,000 credits (+110,000 credits)
Colonel Grade 3: 1,180,000 credits (+110,000 credits)
Brigadier: 1,400,000 credits (+220,000 credits)
Brigadier Grade 1: 1,520,000 credits (+120,000 credits)
Brigadier Grade 2: 1,640,000 credits (+120,000 credits)
Brigadier Grade 3: 1,760,000 credits (+120,000 credits)
General: 2,000,000 credits (+240,000 credits)
General Grade 1: 2,200,000 credits (+200,000 credits)
General Grade 2: 2,350,000 credits (+150,000 credits)
General Grade 3: 2,500,000 credits (+150,000 credits)
General Grade 4: 2,650,000 credits (+150,000 credits)
Field Marshall: 3,000,000 credits (+350,000 credits)
Hero: 3,700,000 credits (+700,000 credits)
Legend: 4,600,000 credits (+900,000 credits)
Mythic: 5,650,000 credits (+1,050,000 credits)
Noble: 7,000,000 credits (+1,350,000 credits)
Eclipse: 8,500,000 credits (+1,500,000 credits)
Nova: 11,000,000 credits (+2,500,000 credits)
Forerunner: 13,000,000 credits (+2,000,000 credits)
Reclaimer: 16,500,000 credits (+3,500,000 credits)
Inheritor: 20,000,000 credits (+3,500,000 credits)



That's it for now. I will later add the other Waypoint stuff (MP and CQB attachments).

 

Update: Avatar Awards added.

 

It IS there but i accidentally called it Assault/Sapper[R] instead of Collar/Breacher[R].