Spartan
EVA:
Body: Complete Tsavo highway on any difficulty but easy
Shoulders: Complete the ark on any difficulty but easy
Head: Complete Campaign on normal
EOD:
Body: Complete Tsavo highway on legendary
Shoulders: Complete the ark on legendary
Head: complete campaign on legendary
Security:
Shoulders: Earn 750 gamerscore
Earn 1000 gamerscore
Scout
Body: Unlock 'too close to the sun' achievement
Shoulders: Unlock 'were in for some chop' achievement
Head: Unlock 'used car salesmen' achievement
Mark V:
Head: Unlock 'UNSC Spartan' achievement
ODST
Head: Unlock 'spartan graduate' achievement
Rogue:
Head: Unlock 'spartan officer' achievement
Elite
Flight
Body: Complete Tsavo highway on heroic or legendary
Shoulders: Complete the Ark on heroic or legendary
Head: Complete campaign on heroic
Ascetic:
Body: Unlock 'up close and personal' achievement
Shoulders: Unlock 'overkill' achievement
Head: Unlock 'steppin razor' achievement
Commando
Body: Unlock 'triple kill' achievement
Shoulders: Unlock 'killing frenzie' achievement
Head: Unlock 'overkill' acheivement
Recon is only given to bungie employees or to gamers under extenuating circumstances. Hopefully one day they will offer it to everyone. | 
July 23rd 2009, 3:33 pm by VDGfreak