I only made it about halfway through The Magicians before it got too pretentious and, for lack of a better term, "literary" or Catcher-In-the-Rye-esque for me. I think I read the first part (at the school) and got increasingly fed up and weirded out by it until I just couldn't focus/enjoy anymore and I didn't read part 2.
I agree with Wren that Mieville's Un Lun Dun is a lot like Neverwhere. I read the two books several years apart and I enjoyed Un Lun Dun, but it ended up being a slow read for me.
My personal favorite author is Jacqueline Carey - she has three trilogies set in an alternate-historical-fiction world. The first trilogy and to some extent the second has explicit as well as dark sexual content - on the other hand there's a lot of "traditional" fantasy I can't really enjoy because it's so violent, so I presume her stuff is not that bad as long as you're okay with the sexual angle (it's almost entirely consensual). (I always feel the need to Warn People What They Are Getting Into with these books, and then I read a recommendation from someone I know via WoW that's like two hundred pages of beheadings and rapes and I figure you guys don't care about a little sadomasochism, but you never know.)
The second trilogy gets a lot more gushy romantic near the end although there's still an epic fantasy storyline going on as well. The third trilogy is a little more mainstream so far (only the first book is out, the second is due in June). She also has a duology that's more traditional-fantasy that I haven't read, although it's supposedly not as good, and a complete genre switch in a paranormal/contemporary book called Santa Olivia.