Best games ive played in 3d are mainly RPG`s but may favorite atm are :
Darksiders- easy to play and not to much concentration, very good to get used to the eye strain.
Mafia 2- very enjoyable in 3d and the aiming mechanics work well in 3d.
Devil May Cry 4- currently the only 3d game ive seen where things come out of the screen aswell as amazing depth.
Just Cause 2- just stunning 3d graphics.
Bad Company 2- Stunning Graphics but aiming is very uncomftable.
as far as your suggested games go i havent played any assassins creed games in 3d yet but im sure there impressive but i havent had many good experiances with FPS games as aiming is quite difficult and the crosshairs havent been correct in any games ive played so far.