Huge thanks to Horace for this list (which is much simpler to understand than Marriott's T&Cs!)

Daily Breakfast for Platinum Elite (and higher)

Six categories:

1. Breakfast for member + 1 in the lounge. If the hotel does not have a lounge or the lounge is closed, member can choose 750 points OR breakfast for member + 1. A limited number of hotels provide 1,000 points each day the lounge is closed instead of a choice. Any of these benefits are in addition to the Platinum Elite welcome gift.

— Autograph Collection (excluding resorts)
— Courtyard (only at a limited number of hotels, all of which are outside of North America)
— Delta (excluding resorts)
— JW Marriott (excluding resorts)
— Marriott (excluding resorts)
— Renaissance (excluding resorts)

2. Breakfast in the hotel restaurant for member + 1 as a Platinum Elite welcome gift option (not in addition to it).

— Aloft
— Autograph Collection (resorts only)
— Delta (resorts only)
— Four Points
— The Luxury Collection
— JW Marriott (resorts only)
— Le Méridien
— Marriott (resorts only)
— Protea
— Renaissance (resorts only)
— St. Regis
— Sheraton
— Tribute Portfolio
— W Hotels
— Westin

3. Breakfast in lounge for member + 1, if the hotel has a lounge. This is in addition to the Platinum Elite welcome gift, which could be breakfast for member + 1 in the restaurant. No alternative benefit if the lounge is closed.

— Le Méridien (only at locations with a lounge)
— Sheraton (only at locations with a lounge)
— Westin (only at locations with a lounge)

4. Daily $10 F&B credit for member + 1 as a Platinum Elite welcome gift option (not in addition to it). Can be applied toward breakfast or toward other F&B purchase in the hotel restaurant or bar.

— AC Hotels
— Courtyard (locations without a lounge only, which means most locations)
— MOXY

5. Breakfast for all guests included in room rate, regardless of status or membership

— Element
— Fairfield
— Residence Inn
— SpringHill Suites
— TownePlace Suites

6. No complimentary daily breakfast, even for Platinum Elite

— Design Hotels
— Edition
— Gaylord Hotels
— Marriott Executive Apartments / ExecuStay
— Marriott Vacation Club / MVC Pulse / Grand Residences by Marriott
— The Ritz-Carlton
— Vistana / Sheraton Vacation Club / Westin Vacation Club