 If you liked
Yureka
|
 ...then you might like
.hack//Another Birth
|
They both involve going into an online game. Even though this is the novel version I'm recommending compared to the manga, I did that because I think it's the best version of the .Hack series that have the true story line in it.
Both art styles are attractive (even though AnotherBirth is a novel it does have some images in it at times)