Firstly, you can <a href="http://beta.systemrequirementslab.com/srl/intro.aspx">go here</a> to check system requirements for these games you're thinking of.

Secondly, comments on specific games.

1) Dark age of camelot is very PvP focused, from what I hear. That may or may not be your thing. It's also a fairly old game, and past its prime; it has about a fifth the subscribers it once did.

Yeah, what mostly caught my eye was the character, there are very many options there.

2) Lineage 2 has almost identical system requirements to Aion. If you can't play Aion, you probably can't play L2. Also, Lineage 2 has been criticized pretty heavily for being nothing but a huge grind fest. Keep that in mind.

Ah, that's not good then. I should probably not try that then. Especially not since I would have to buy the game to try it.

Lastly, suggestions.

1) Aion. It's supposed to be similar to WoW, while providing some very different play mechanics that provide a unique experience. If you like WoW but just want something new, you'd probably be comfortable with Aion.

It looks very interesting and thanks to your link I know I meet the min req. It's just my ram that's too low for recommended. Well, it said my video card was too low, but all subcategories was ok it said.

2) EVE online. If you're burned out on WoW and want something completely new, EVE will give it to you. It's something of a polarizing game, but the people who like it REALLY like it. On the other hand, it is very corp (guild) centric, so you may find there's not enough single player content for your taste.

I haven't dared try it, it pops up ads about it every time I start
Steam. I really prefer the fantasy based games, space is not really for me.

3) Champions online. Supposedly a ton of fun, and very easy to play casually. The catch is that the system requirements are a bit higher than for the other games on this list.

Apparently I have the same problem for this game. Min req are good, but my ram and video card don't reach up. They stopped making the ram I have and the alternative is very expensive(for me). And it don't really look like my kind of game.

4) Wait for Star Wars: The Old Republic. It's still a little ways off, but it's looking amazing in every aspect thus far. Take a break from MMOs and come back when there's a worthy successor to WoW.