I'm Marriott Gold through United. (Though, I'll come close to an independent requalification this year due to the excellent perks I've received.)

Was upgraded from a deluxe room at the Renaissance Phuket Resort & Spa to one of their private pool villas for a 4 night weekend, a $700 per night room.

I was also upgraded in Bangkok at the Marriott Executive Apartments Sukhumvit Park from a regular 1BR to a large 1BR for a 30 day stay. They also included free internet and free daily buffet breakfast.

I probably couldn't count the upgrades I've gotten as a Marriott Gold this year. The benefits are amazing and have mostly kept me loyal to Marriott since last year.