Here is the full list of all 36 Tom Clancy's Rainbow Six Vegas achievements worth 1,000 gamerscore.
Complete all maps of splitscreen Terrorist Hunt on Normal difficulty
Complete all maps in splitscreen T-Hunt at Realistic difficulty
Achieve the rank of Elite
Most kills in a ranked online Sharpshooter match
Most kills in a winning online ranked match of Team Sharpshooter
Most kills in a winning online ranked match of Team Survival
Be the only remaining player in a ranked online match of Survival
Leading contributor of kills for the Defenders in a winning Attack & Defend ranked match
Recover the Intel in Attack & Defend within 2 minutes
Host a 16-player match
Play all maps of every Adversarial game mode
10 kills using a Sniper rifle in an online ranked match
Achieve the rank of Lieutenant 2nd Class
10 consecutive player kills without dying
Deposit the canister and kill an enemy canister carrier in the same Retrieval match
Used all Gadgets at least once in single player Story
Defuse the bomb within 2 minutes in Attack & Defend
Kill 50 players using Explosives only
Rescue all hostages in an Attack & Defend mission in under 5 minutes
100 total player kills in any adversarial mode
Completed Nevada Dam in single player Story Mode
Complete the single player Story Mode at Realistic difficulty
5 consecutive player kills without dying
Cooperatively complete the Story Mode
Kill 150 terrorists using only a Pistol
Completed Dante’s Casino in single player Story Mode
Achieve the rank of Private 1st Class
Completed Vertigo Spire in single player Story Mode
Completed Downtown Vegas in single player Story Mode
Completed Calypso Casino in single player Story Mode
Complete a Cooperative Story mission with at least one other player
Completed Border Town in single player Story Mode
Kill 500 terrorists online or offline
Cooperatively complete all Terrorist Hunt missions
Complete a Cooperative T-Hunt mission with at least one other player
Used the Xbox Live Vision to create a character with your appearance