We're at a really low point in MMO gaming. I've been here every step of the way, and love the genre, but it's stale right now. Here's a list of my all time favorites though.
Loved:
Everquest (
www.everquest.com you can check out the new Agnarr server which is very populated, or
www.project1999.com for a free emulated version of how EQ was in 1999)
Dark Age of Camelot (
www.darkageofcamelot.com In a bad state on live, but they are launching a 'fresh start free to play' server in the 'near future', so stay tuned)
World of Warcraft (A string of bad expansions have brought this mighty titan low, but Legion isn't bad. It's fun, just doesn't have the sticking power for old timers like me. Also launching a new "classic" server soon
www.worldofwarcraft.com)
Guild Wars 1 (Brought 'Arena' to MMO's, for better or worse...)
Edit: Albion Online was an amazing ride early on. Sucks they sold out, but the first couple months this game was out, it was magical:
Full loot. Beautiful open world, FFA PvP. No fucks given, balls to the wall. Just imagine the though of encountering another group of adventurers in the world, and fighting it out. Winner take all.
Liked:
Warhammer: Age of Reckoning (Dead/Defunct, RIP)
Guild Wars 2
Elder Scrolls Online (Fun game when it launched, and I hear it's gotten better...)
Didn't like:
Rift
Tera
Aion
Archeage
Runescape
Ultima Online
Lineage 2
Blade and Soul
(notice how most of these are Korean games?)