Shimano XTR on my Niner Jet 9 RDO- Nothing comes close. I might let a White Industries crank sneak on there this winter just for grins though.

On road? Campy Chorus 10 speed for a modern groupset. It's pretty much set and forget. Plenty of performance for me. However, I did ride a friend's Raleigh Tamland with Ultegra 11 speed last week and I might be talked into that at some point as well. It's very, very nice.

Vintage? I'm with AAZ. I loved the Shimano DA 7400 series. Pretty much ended the Campy fixation for me. I never bothered with Campy again until five years ago when OFG got me interested.