Stumpjumper is a great choice at that price range. I like that frame a lot. If you like the feel and position on a road bike, Gary Fischer may be a good choice. Specially their genesis geometry. Aluminium hardtails have come a long way and offers good durability, so not much worry there.
Apart from stumpjumpers, I would suggest checking out
Kona Kula (
http://www.konaworld.com/bikes/2k7/KULA/index.html). a bit above your price range but this is a great light bike. I dont know why, but I love the way kona bikes ride and handles. They are my favorite hardtails. Also, check with your local Kona dealers they may have a 2006 model and may offer you good discout.
Iron Horse Worrior Race or Expert would also be good choices.
I am not a fan of Trek. some of their bikes are nice, but they are often overpriced (in my personal opinion).