Think about it this way...you wake up on a Sunday morning needing something greasy and delicious, you call a friend, they're desperately in need of curing their hangover. You decide to hit up a local brunch spot. In Manhattan, this can end early, with a $50 bill and only a mimosa or two down the hatch. BUT, there are a few places that have the answer for you. Your brunch comes with an all-you-can-drink deal...you won't be able to stop. It's a beautiful thing to make friends with the people sitting next to you at 12:30 on a Sunday because you've all had 6 mimosas and your bill won't be higher than $23/person...with tip. Everyone is happy. Everyone is drunk. Everyone is well-fed. It is truly a beautiful thing.
(Try, but make reservations: "The Sunburnt Cow", Ave C @ 9th St, $18/all you can drink+food, "Bondi Road", Rivington St. @ Suffolk, $18/all you can drink + food, "Essex", Essex @ Rivington, 3 drinks+ food/$16)
If you don't live in NYC...visit...or just move already. Plus, I'm sure there's more of these deals around that I just don't know about yet.