If you like shooting get modern warfare 2. (short campaign, get for multiplayer)
If you need a long campaign get borderlands (rpg shooter, 50hours or less to beat, cartoonie graphics though)

For action I’d go with Assassins Creed 2 or GTA4. I logged around 19 hours on AC:2 on a single play through. GTA4 is very long. WAY over 40+ hours of game.

For a good rpg get Oblivion Elder Scrolls IV (its only like 15-20 bucks) Long, long campaign. Or go for dragon age: origins (around 40-60 hours to beat maybe).

For strategy I’d go with halo: wars I guess.

For sports get the new fight night round 4 or the new maden nfl 2010.

For racing go with Forza Motorsports 3 or Need for Speed: Shift (I personally went with Shift.)

All in all it depends on which genre you like more. Although i mean if you don’t have GTA4 yet i’d buy it to (everyone likes it) its long and the freeroam is amazing. Make sure to shop on ebay. You can get all of the above games for %40-70 off of the price than if you bought them in a regular store. Yes, used games work fine. Just check the condition Acceptable, good, very good, Like New (or mint). Out of your game list you have i’ll go ahead and tell you the ones not to get. Don’t get starwars or avatar neither of them are very good. Hope this has helped you in some way. Have a great day kind sir.