Well, I've tried quite a few of those games, and I voted Guild Wars.
WoW: Seriously, I don't know how to describe it. The only purpose is to grind until you get money/gear/exp. Then, when you hit level 80, 70, or 60(got bored at 36) you do important things.
EVE Online: Not enough interaction. I would have liked it if it were you manually controlling your ship.
Runescape: Absolutely terrible, it's what happens when you put up MMOs for free. They aren't well done and they have bad graphics.
CoV: This bored me before level 2(recently). I could not stand the slow travel, especially when you're a SUPER VILLAIN. Shouldn't you at least get some kind of vehicle? But no, travel powers are for people level 14 or something. The holiday jetpack a few years ago interested me, I made it to lvl 5, then the holidays were over. The game became a standard MMORPG.
Hellgate: London: I have to say, this looked great at first. Almost like if Bethesda made an MMO, except no open world. I loved how each person saw their own loot, really helped in multiplayer. However, they never really got rid of the lag and people slowly stopped playing it. I don't know why I stopped, it's an MMORPFPS, and it was okay.
Guild Wars: This is like WoW, but less people, so it isn't crowded. You also get to recruit NPCs, so that's a plus. My favorite part was that you get to choose 2 Professions(classes) so you don't have to choose. Elementalist Necromancer! Necromancer Monk! No WoW proffesions, though, which was actually one good thing in Warcraft. Also, no monthly fees.
Edit:
Warhammer: Age of Reckoning(WAR): I, sadly, did not play this right and though I like PvP better than PvE, I didn't know you could just PvP from level 1! I do think that the game itself was good, just missing something. I'm not exactly sure what. Greenskins were pretty funny.
"Write some words" "Wot's this? Words wif no pictures? You're crazy!"
I's is doin' good job speakin' da good Orky langwich!