I like Halo, Everlasting and Fairytale. c:
Good Luck choosing Karen!
Hmm, I'd have to say. Crossroad. Halo and Free are nice but they remind me of video games. Crossroad seems heavier? If that makes sense? I don't know. I just really like that one. Good luck with your decision. :D

Ive changed my name 3 times so I agree with the whole waiting until you're absolutely sure. Out of your list I really really like Free. Fairytale and Lights are a close second and third.
I don't like Crossroad and Endings much because those seem to be a point in life you're not often at and I'd wonder how long that name would be special to you if you had it.
[tot=london]
I like the username you already have, but if you really want to change it then I would say go with Lights. ^^
[flower=Emily]
I love fairytale and crossroad, I'm rather amazed that fairytale isn't taken already. o_o; It's so cool!
I'd go for Halo or Crossroad. Those two are the nicest, I think.
I think Halo and Fairytale are really cute. Free is too. ^^
I like Halo the best. ;D
But if it was me, I would go for fairytale.
My personal favorites are ashburn and endings, but admittedly I do like ashburn slightly more.
Personally I like halo and free the most. I prefer shorter names over longer ones. I think those would make interesting usernames. I think it would be amazing if you had a user lookup that goes with your username.
i love halo, but i think i'd choose fairytale from your list.
I vote for Halo; as others already said it's short and a really nice name. Good luck with your decision. :)
I wouldn't choose Halo, but Free. Halo just reminds me of death ._. Free is much more... free XD Positive ^^
Free has so much interesting story potentials (coming from rabid storyteller) But Halo is really nice too... Hmmmm. Any of those two seem good.
I really really like Free :) You could do so much with that (in terms of HA etc.)