Sadly if you don't want to play any carebear MMOs you will have to fork out some money. Most of the free to play MMOs suck sooo much because of the following reasons:
- Heavily instanced. It sometimes feels like you are playing a single player game.
- PvE oriented. You can't freely attack any other player.
- Fast travel. Some MMOs allow you to just fast travel to certain zones without any penalty. LAME!
- Global chat capabilities... This destroys the roleplaying experience
- Some Free to play MMOs offer better stuff to paying customers.
- Gets boring real fast because of the above reasons
If you are a trammie(carebear player) then Runes of Magic is an okish game. Feels alot like World of Warcraft.
If you are looking for a modern sandbox MMO and have the money then look at Darkfall or Mortal Online.
If you don't have the cash then rather play Ultima Online: Second Age. It has the ruleset before EA destroyed the game by adding Trammel(Carebear land). Most MMOs(including WoW) follow the Trammel approach to gameplay that is reaally boring.
You can find out more about UOSA here:
http://www.uosecondage.com/