Great MMORPG F2P?

The Lord of the Rings Online.

I recommend living in 2005, where they weren't played out.

Hmmm, if you like Star Wars and/or Bioware story games, the Old Republic is free, and far from the worst game I've ever played. Just ignore all the random things designed to annoy you into subscribing, because there's quite a lot of them... :)

But if you don't already like Star Wars or Bioware, don't waste your time. There's better free stuff elsewhere, as everyone already mentioned... :)

I see they were already mentioned, I suggest Neverwinter and/or Tera.

Guild Wars 2.

EDIT: If you mean no subscription fee*

There's no such thing.

It depends on your taste, Most MMOs have too many toolbars and numbers stiff character movements and, lack of immersion in the game, and 99% of MMOs have the exact same thing, "Kill 10/10" or "Gather 100/100" from level 0 to 100, Tera has an interesting combat system {besides the main atk for sorcerer which is repetitive as fuck} but besides that literally the entire game is Kill or Gather and Grind over and over and over again, now if you're into that, have fun.
But if you're not, Pirates of The Burning Sea is a free pirate MMO, with huge exploration, unique quests, great ship to ship combat, pretty average 3rd person combat, ability to customize Sails, Mast, Cannons, Bullets, Gun Powder, to craft sell and buy and steal and find a lot of shit, several nations to pick for your character with each a unique storyline and quests which some have multiple paths affecting your reputation with each, also an interesting on going War and PVP zones, created from causing trouble near ports, and a player governor for each commanded port of your nation.
Eden Eternal is pretty great, it WAS near perfect but now with a new update a lot of the immersion got broken, but the combat system still pretty great, unlike other MMOs you can feel and clearly see when you get hit, or deal dmg, with little custom animations and effects, simple things that make the immersion of Eden way better, tho all quests are pretty much "Kill" or "Gather" or "Activate", a lot of custom shit tho too that is fun, fashion shit, and cool dungeons, and no need for Massive grindings.
So is just, pick what you're into. If you're not bothered by Grinding the whole game. Or how most MMOs handle combat and hitboxes, most games would make you happy.
And for the record, before any twelve year old start to bitch about their favorite, I never said Tera or what ever is bad, it is more of a preference thing.

Lineage 2

Tera is da best, or GW2 (buy to play :D)

Spiral Knights and Realm of the Mad God are both on steam, they're awesome and incredibly addicting. They're F2P too (though Realm of the Mad God has lately put a lot of real money crap, but it's just crap, who cares). I almost feel ashamed for having abandoned them.

Hmmmm i say Rift :)

Guild Wars 2 is buy to play but definitely worth it.

For free to play I'd suggest one of these: Eden Eternal, Dragon Nest, DC Universe Online, Marvel Heroes, Rift, Lord of the Rings Online, Runes of Magic.

I played TERA for a couple of hours and it's k.
Too many people playing lolicon garbage in it though.

Atlantica Online

Is a great game that took mounts of my free time :(

Ragnarok (not Ragnarok 2!)
TERA is a good one too.