Travian works well enough. As far as free-to-play MMOs go, though, the one you want to look at is Dungeons and Dragons online. It's shifting for a Free-2-Play setup soon (with the requisite little customizations you can purchase with real money) because it hasn't been making enough, the logic behind it being "Well, I can just play Dungeons and Dragons for real." That said, if you're not into tabletop, look at it and give it a shot. Guild Wars is also right up there, and is honestly one of the bigger WoW rivals to come into place. It's free-to-play, but REALLY deep and VERY fun, especially if you're looking for something more immediate and PvP based and you don't wanna wait for DnD to get it's ass in gear.
Other notable Free-2-Play ones are Sword of the New World (you control a three-man party in game instead of one, central character, European Colonies setting with guns, swords, magic, etc.), and if you're just looking for something to tool around with at the office you could jump on Maplestory (side-scrolling, adventure based RPG), Runescape (REALLY old Java-based MMO for cheap), or any others. Silkroad (European/Asian conflicts, without actually being European/Asian) is interesting because each respective culture has it's own class system. If you're looking for something you could pay for, City of Heroes/Villains is actually really interesting, with a very-easy-to-understand, hard-to-minmax combat system that you can customize for either fluff or hard-hitting gameplay.
If all fails, I've got a whole bunch of tabletop stuff on PDF I could send. ^^;