Lots of good possibilities mentioned here. Might also check out REI if there is one in your area. Some good bikes, good warranty, currently 20% off for members (would be worth joining for the discount), and free shipping if it is ordered online. I think REI might have some bikes that might interest you. If you select show all bikes, you can then specify things like disc brakes, frame material, etc. on the left of the page to get an idea of what is available that may interest you.