Club Penguin!!!

I made myself giggle.

Anarchy Online

Rift
You'll not find a better full featured mmo.

Guild wars. the original. Martial Heroes is my favorite F2P option.

I tried C9, the combat mechanics are nice, but it's a bit laggy on my crap-top. Also gets repetitive very quickly, all quests require you to complete a dungeon in different difficulties...
I don't really have a favourite one, I played 12sky2 and MUO for quite a long time, but now I regret playing both of those games.

Super mario kart

Even though it doesn't really count: Torchlight 2.

I've played Spiral Knights and Realm of the Mad God. You can get pretty far in both without paying, they are both pretty awesome.

I did enjoy my 3.5 yrs i spent in Final Fantasy 11. However, I must say the absolute BEST times I have had would be a tie between Guild Wars 1 and 2. The fact that I do not feel tied to the game, can easily lose hours playing it, and the awesome community really put it above and beyond.

It was WoW for me so far. But installing guild wars 2 now, just arrived :)

Lineage 2 ! :)

Dark Age of Camelot, pre ToA that is :)

played many MMORPGs

must say that one of the best in Lord of the rings online... (if u like the book and its plot u will enjoy the game ^^ )

but i love GW2

i would say GW2 =P

Well, I'm still enjoying Guild Wars 2, so I guess I'll vote for that.

Rift!

Out of Final Fantasy 11, Everquest 2, WoW, Warhammer Online, and Aion...

...it's WoW, easily. So polished compared with the others, my experience was middling until I hit the level cap (Burning Crusade era) when everything opened up and I sank in a quite frankly ridiculous amount of time. The art style drew me in as well, some people criticize it for being too "cartoony" or somehow childish but I found it far more appealing than the more drab and "realistic" styles found elsewhere.

Ultima Online. So many great times and awesome people i met. Alot of awesome Free shard's aswell.

World of Warcraft and now Aion ^^

Sad to say because I play very few of MMORPGs. Its WoW.

Life.

Ragnarok Online and Atlantica Online is where I spent a shitton of time on. Maple Story was fun back in the day too.

Ultima online and Fallen earth, ive played many and most of the mentioned here + special place for Shin megami tensei imagine online its fun

C9 - Continent Of The Ninth

City of Heroes
A look at the game here

WoW for atmosphere and friends. TERA for combat and visuals. (It's an unbelievably beautiful game, even compared to single player ones.)

There is no such thing as good MMORPG. :)