Ace In The Hole

Dawg, main man, buddy, the guy that always agrees with you.

Yo, this is my ace in the hole.

good day to you, sir

Somthing said by low level employees of hotels, cafes, tea-and-crumpet shops, and most of England (Except Northern Ireland, where it is replaced by "Top O' de mornin' to ye, laddie!").
TransGender: 'Sir' can be replaced by 'Ma'm'.

Doorman: Good day to you, sir. You're looking very professional today.
Buisnessman on a bad day: Shut up, you freakin' pansy.