First of all determine what you need for how you ride, hardtail, full susp, DH setup. Then go to your LBS and start trying the different brands out, if you don't like any there, go to another store with different brands. See if they will let you take it to the trail for a test ride, if they don't I would consider finding another LBS. If your spending $1800 in my opinion you have every right to test it out on actual terrain you'll be biking on. Don't get to wild however and damage the bike.
As for brands, everybody is different in their likes and dislikes. I have a Klein which I don't believe they make anymore. Gary Fisher is a very popular bike around here. I haven't researched new bikes in several years, but the Sugar Gary Fisher made was a pretty darn good bike. Also if you can wait until the end of the season, you may find a lot of deals especially if bike gear ends up being oversupplied and under demanded as ski gear was this season. (at least in the Northwest).