Hey Dude,
Hope this long long list helps you out!
Madden NFL 06: Very easy to get all 1000 in an afternoon. It takes a while to sim 30 years of franchise, though.
Tiger Woods PGA Tour 06: Some crazy online stuff, but the single player achievements are easy enough. Not recommended if you don’t intend to play a lot.
Need for Speed Most Wanted: You earn all 1000 by simply playing through the game.
Project Gotham Racing 3: You earn most of them just by playing the game and collecting cars. It is hard to get them all, but you’ll have fun doing it.
Kameo: Elements of Power: You get most of them by simply playing through the game. You also get them for earning “A” Rankings in each temple.
Gun: The game is short and easy, but you get lots of achievements and points for playing through it.
Tony Hawk’s American Wasteland: You get most of them for playing through the story and classic modes. Easy if you are THPS fan.
King Kong: You get all 1000 just by playing through the game.
Condemned: Criminal Origins: You get most of them while playing through the game. The rest are associated with hidden items that are easy enough to find.
Full Auto: Just play through the game to get most of them. Some achievements are for Xbox Live stuff, but most of the points are for single-player.
Fight Night Round 3: Very, very easy to earn all 1000. Just play single-player.
Ghost Recon: Advance Warfighter: Split fairly even between single-player and Xbox Live. You’ll have lots of fun doing it.
Elder Scrolls IV: Oblivion: Earning all 1000 points isn’t all that hard, but it might take you 100 hours to do it. You’ll love every minute of it, though.
Top Spin 2: Most of the points are earned in single-player. It can be difficult, but once you get over the learning curve it isn’t too bad.
Amped 3: Earn them all by playing through single-player. Very underrated game that is highly recommended.
Tomb Raider Legend: Just play through the game to earn most of the points.
X-Men 3: Play through the game to earn them all.
Rockstar Table Tennis: Pretty easy to get most of the points, and a blast to play online.
Hitman: Blood Money: Earned by playing through the game on various difficulties. Not an easy task, but fun enough to keep you playing.
LotR: Battle for Middle Earth II: Most achievements are for single-player. Lots of fun.
Prey: You get 600+ points just playing through the story missions, and since you can never die it is insanely easy.
NCAA Football 2007: Easy points if you intend on playing it quite a bit.
Dead Rising: Most of the achievements are easy. There are a couple tough ones, but the game is so fun you won’t mind.
Ninety Nine Nights: Most achievements are earned by simply playing through the game.
Madden NFL 07: Not as stupid-easy as Madden 06, but you can simulate games and earn most of the achievements.
Lego Star Wars II: You earn most of them by playing through the game. Achievements for beating each level without dying are hard, but not impossible.
Enchanted Arms: You get all of them for playing through the game.
The Godfather: You earn most of them over the course of the game.
Saints Row: You get most of them in single-player. Very fun.
Test Drive Unlimited: You earn most of them just playing the game normally.
NBA 2K6: Insanely easy to earn all 1000. Lower the difficulty and extend the time to a full 48 minutes and you can get them all in one game.
NHL 2K7: Between using sliders to make the game very easy and simulating through dynasty mode, you can earn most of these achievements easily.
Just Caue: You earn all of them playing through the game normally.
NBA Live 07: Most of them are just rewards for playing with the superstar freestyle controls.
Splinter Cell Double Agent: You earn most by playing through the game.
Tiger Woods PGA Tour 07: Most of them are for playing through career and trying all of the modes.
Marvel Ultimate Alliance: Very easy, just play through the game.
FIFA 07: Earned just by playing the game. Some take a while, but it is worth it.
Tony Hawk's Project 8: You get most by simply playing through the game normally.
Gears of War: A good balance between single and multiplayer. Very enjoyable to earn.
Phantasy Star Universe: Very easy as all of them are earned through playing the single player.
Gamertag: Pezza Dispenser