As most of you know by now:
United, United, United: Premex last 2 years (maybe 1k this year??), prmier for 2 years before that. Countless upgrades, award tix (for family), hotel transfers, etc. since...
Useless (sorry, just can't resist) Chairman preferred, or whatever they called it, for 2 years before that. Still have 12,000 miles locked in the USAirtight vault.
Have Delta, American and America West just because I signed up when I got bumped and wanted to double-dip.
Hhonors: use lots and lots of awards
Marriott: points to UA
Hyatt: personal first choice but my company's last!
Hertz #1 club gold