Mass Effect, and if you have to ask me why I say that. You don't know me well.

I loved them all for different reasons
Mass Effect had an awesome story and decent leveling system
Fable 2 had a fun story but it was too easy to max out the character, I got everything from magic to emotions in no time and a lot of extras to do like buying every house
Fallout 3 had the VATS system which was fun and a decent story, but it had my favorite leveling system except the cap on leveling.

I don't think I could recommend one over the other.

Mass Effect, Fallout 3 as a really close second...

Morrowind

for once i agree.

wait is it the first time?

Demon's Souls. It's a WRPG at heart, and the best damn RPG I've played in years.

But if I have to chose between just those three, I'd go with Fable.

FALLOUT 3!!!!!!!!!!!!

I never played Mass Effect and I didn't really like Fable 2. Fallout had a great story, VATS system, and they pulled of the whole post apocalyptic theme with a possibility to save a piece of humanity

I loved Mass Effect, and Fallout 3. I have yet to try Fable 2.

Diablo II says hi