Conrad Singapore - were very accommodating with last minute changes due to airline snafus, including applying $$ from advance purchase booking to later night. Said it was because of my Diamond status. Also, the lounge is the best I have experienced in the Hilton family.

Hilton Grand Seoul - effusive welcome and greetings throughout stay, best welcome amenity (bottle of wine, big plate of canapes, fruit), nice lounge.

Hilton Southlake, TX - usually get a nice suite upgrade, excellent lounge for breakfast (attendant always seems to know my name). However, I'm not sure whether the nice treatment is due to solely to Diamond status or also due to the frequency of my stays.