My best suggestion would be American God's by Neill Gaiman. Probably the best modern novel I have ever read. Better than choke and enders game, even though I really liked both of those as well. It definitely meets the freaky, weird and intelligent quota.
I'm surprised this only got one vote, so far. I definitely second it. One of the most effed up things I remember reading was when he wrote himself into the story, but as the author of the book near the end of Breakfast of Champions. I really enjoyed that, but I think my favortie is God Bless you Mr. Rosewater. I think its out of print, but I got an old copy of it off www.half.com for $1 or something insanely cheap.