Minado used to offer the birthday person (with proof via license) a free future meal when they came with a rather sizeable party.
Bugaboo Creek (RIP to the Watertown location, loved their Prime Rib) would send out a moose head puppet and a free dessert for a birthday celebration.
If you're on the email list or a member of their card club, you will receive a coupon for a free dessert at Finale Desserterie & Bakery, a free small sundae at JP Licks, a free meal at Not Your Average Joe's.
At the Texas Roadhouse they bring over a saddle for the birthday person to sit on and sing to them.
Salts in Cambridge will decorate your table and garnish your purchased dessert if you let them know ahead of time that you're celebrating.
What other spots will do something special for a birthday? And do you need to go the actual day, or just be out celebrating, or sign up ahead of time?