Seeing as I had a similar query a couple of weeks back, I would go for a the Specialized. I tried a Marin, Spesh, and some others. the Spesh was the best one by far. But then you gotta give 'em all a good ride. To begin with the Spesh was low down my list.
well I try to get sponsered by my missus but she regualy denies me spending my money, so mostly im sponsered by my own company....and the wages it pays me.
I've never ridden any of the three but there's at least one of each in the group I ride with. They're all very competent and cope with Peaks riding both up and down. Having said that, of the three I'd start with the Mongoose.
Actually, I wanted to buy my Spesh, but my boss got the deal for me when I asked. To be fair, at work we do Trek, Giant and Spesh, I probably wouldnt buy any of the Treks, some, but not all Giants are good. Spesh wins in most deparments though.
My Epic is the best XC MTB I've ridden, the Enduro is much more fun than a Reign, but doesnt pedal as well. My Tarmac is the best road bike I've ridden.
The new ones manual so easily, they're brilliant! Infact, one of the guys at work took loads of pics of me messing around on one in the park the otherday, I'll have to upload them.
FWIW I ride in the Peaks most weeks and have a hardtail so suss isn't a pre-requisite. But if that's your bag then you need to bear in mind the fact that you will encounter lots of crap and have abrasive gritstone terrain to contend with that eats bikes for a laugh. So simple designs will be a bonus.
I used to have a single pivot East Peak which was a great bike for round the Peaks so the new one is probably a safe bet.
IMO an obvious omission from the list is the GT IDXC range. They seem like a simpler version of the Mongoose and just as good value.