Dunno if I'm spoiled or just hard to please, but when I think of games like Baldur's Gate 2 which with mods was easily over 100 hours and Throne of Bhaal which was 30-40 (might be wrong), I kind of feel cheated when I pay good money for a 20 hour RPG. I realize that yes, the games are MUCH more like movies and more immersive, more expensive to create etc. I really like marathon RPG's. In my mind BG2 is easily more epic than anything that's been released since. Even Fallout 3 was decent for what it was, but the first two were vastly better. I hope that some serious DLC comes out for Mass Effect 2. Same with Dragon Age, for that matter. I haven't played yet, but I have an Impulse copy on pre-order (probably should have gone box).
I was watching a guy play live stream earlier and I spoiled a few things for myself, but the funny part was that he kept saying "I'm nowhere near the end of this game" and he was 21 hours in. Then suddenly he started a new quest and found that he was at the end of the game. Kind of made me chuckle. Sorry for the long post.