Looking for suggestions on a Mt. Bike

[shotking]

Very shortly i'm gonna be in the market for a new mountain bike. A new guy who just started workin with me is into it hardcore and he got me reinterested in the sport. Only problem is he claims i won't find an acceptable bike for under 1000 bux. I was hopin to not spend over 500. Riding would be mostly cross country and i'd be looking at hardtails. Any one with any brand suggestions wether it would be to look at or to avoid please post. Also is 500 a reasonable limit or do you guys agree with him?