Mass Effect is one of those games that I will remember forever. Much like I'll never forget Ocarina of Time or Super Mario Bros. Not saying that it's better than those games (as they are perfection in gaming form), but it gave me a much stronger set of emotions.
My only gripe was that it was too short. I beat it in about 40 hours, but I'm 60 hours into Dragon Age and barely getting started. I've never beaten a Bioware game other than the Mass Effect games, but I know that they've all been longer than 40 hours.
P.S. I personally liked it more than KotoR, but I dislike the Star Wars universe in general.







