Whats the best mountain bike for a beginner?

My friend is beginner that wants to get into mountain biking. He is interested in buying a decent mountain bike to get started in this sport. Well, he is an athletic and fairly muscular 31 yrs old man, 6'1" tall and weigh 215 pounds.
Please pass on your suggestions.

get a hard tail and dont spend less than a $400 on one make sure you try it before you buy also do a lot of looking about DONT get the 1st one you see. have a look on this site for revews Bikes, Bike Reviews, Cycling Routes, Race News - BikeRadar there is lots of good bikes about for beginners i can recomend merlin malt 1 Merlin Malt 1 Review - BikeRadar iv been riding for about 10yrs and this is the best bike i have had rides very well BUT not sure you can get in the US.

Thank you so much for stopping by bellys1.!! I am grateful to your for your suggestion.

if it was me buying a beginner mountain bike, I would buy a hard tail bike. I would spend atleast $400-500 USD and would ride different brands. Also go to shimano's website and look at the levels of components and try to get the better quality components in the same price point.

I agree get a hardtail for over $400. Best brands I have found is Specialized, Trek, Gary Fisher and Giant.

I have a Specialized Hardrock Sport Disc which works very well for me. Here is the link.

Specialized Bicycle Components : Hardrock Sport Disc