Although I have yet to try any MMORPG, I find that most of the games I try out recently just dont have the kind of exploration I like. For instance, Halo bored me. I like going around everywhere and exploring things, not just going down a mostly linear path blasting the shit out of everything.
This is one thing which dissapointed me about Silent Hill: Homecoming. WAY to linear.
Even with one of the new Tomb Raider games which came out last year, I didn't get the same sense of size, isolation and wonder as I did with the very first two nearly a decade ago. Sigh...