Airline status, hands down.
Since I stay in mainly mid-grade hotels (Courtyard, Hampton, HI Express), I gain almost nothing, save for extra redeemable points, with my loyalty, so I generally spread it around, and hold middling status with several chains.
Insofar as airlines, top status helps the most when things go wrong (WX, MX, etc...), as airlines generally accomodate their top tier folks first. Occasional upgrades and express security lines don't hurt either.