I just bought a new mountain bike have been meaning to start riding more frequently and it was waaaay overdue to upgrade my 1996 GT Karakoram.
I didn't ride any $5k bikes because I know that would ruin my life
I ended up getting last year's 2011 GT Avalanche X (MSRP $1600) for $850. It is a long-travel (140mm front shock) 26er with a decent drivetrain spec, SRAM X7 2x9 with bashguard, basically it is an "all mountain" bike instead of cross-country. That fork is so rad, I am going to get stupid on it already trying to take lines that I'd never do on my old bike
Coolest thing though is on my first ride I ran in to some random bike dudes, all kitted out in their shop jerseys riding 'biker' bikes like a Yeti and a Bianchi. They both thought this rig was a custom build