No no no, pulling a Halo 2 means we'd have to play as Saren >_> But he's dead, so...
I wouldn't mind playing as Garrus, and he's one of my favorite characters in the game, but he's on the same level as Tali, Wrex, Kaidan, and the rest of the crew. I'm not sure why he should get special treatment.
Although giving each member of your crew a rewarding ending wouldn't hurt. Williams gets promoted despite her family background, Tali finds her special thingy for her pilgrimage, Wrex (depending if you let him live) brings the Genophage to an end, Garrus goes up to Spectre ranks, Kaidan (if you let him live) finds and marries that one chick he told you about, and T'Soni does... something.
*shuts up goes back to playing*