Thomson Seatpost, cos they're light and strong and not overly priced (and they sell well too), way better than any other seatpost IMO.
I used to think the same about CK headsets, but these days any £20 cartridge bearinged headset seems to work pretty much as well for long enough for me to have got bored of the frame its attached to anyway! Yes, CK's tend to end up going from frame to frame, but despite how good they are it's a lot to justify spending on one component when something 1/5th the price does the same job. That and 2 out of 3 of my bikes have internal style headsets (one a Campag type, the other a zero stack Can Creek) so CK doesn't cater for them!
Easton bars usually, I like the shape, and 27" is about as wide as I've ever needed. That said the RaceFace bars my latest bike with are quite good too.
Tubeless wheels/tyres, cos punctures suck!
XTR gear cables are indeed a wise move, though recently found the cheap Clarks stuff sold in Halfords to be a fully sealed setup just like XTR. Seems to do the same job for less than half the price! Time will tell but first dozen or so rides through muddy conditions and they still shift like new at least.
Shimano Disc brakes cos they just work. Fit and in general, forget. Unlike most other brands I've experienced at least!
SRAM chains, PC971 usually or a 991 if I can find them for the right price. The quick link is a god send when it comes to removing the chain and they seem to shift better than Shimano chains too.
Bolt through forks cos QR's suck!
Shimano mechs and shifters, preferably XTR M952 (yeah right, though I still have some going strong on one of my bikes) as SRAM feels cheap/nasty and I hate the position of the trigger finger lever on SRAM shifters.