Marin Rocky Ridge, with big fat tubeless tyres and as much or as little lightweight upgrades as you care to pay for.
Cheap enough that you don't get too prissy about it (I've already rubbed all the paint off the headbadge and headtube with my sleeping bag).
Its relatively light (certainly lighter than my 'XC' steel hardtail, despite the coil forks).
It climbs incredibly well, despite the 140mm forks.
I've descended some of scotlands most 'infamous' descents including apparently the steepest trail at innerliethen, some trial bike nonsense at Kinlochleven and the climbers path down the side of Buchaille Etive Mor, the bike handled them superbly.
Its an ace sit and spin enduro bike, I reckon if Rob Lee had one he'd have had an easier time on his double attempt.
Far too boring and not enough rear suspension for many, but I reckon its a classic.