Ok, I need some help choosing my next army. I currently play CSM and absolutely love them. Although I'm not a huge fluff guy, I do like the background story. I love the large amounts of options available to me (yes even in the new codex).

My requirements for my next army are as follows.
-Good balance of fire support and CC
-Models that are fun to assemble and paint and look cool.
-I want it to be slightly challenging, but not a steep learning curve.
-Not MEQ (been there done that)
-Something that doesn't require a huge initial investment just to start playing (both money and time to assemble/paint)

I hope I'm not asking too much. As far as cool looking models Eldar have caught my eye. I've been leaning towards them because of that. But I'm open to anything really.

Any input is greatly appreciated.