When I lived in Staten Island I had a few cool brunch spots that offered unlimited drinks with a set price. A couple of my favorites were Side Street Saloon and Cargo Cafe. Before I left, Cargo Cafe went from unlimited to one drink included, but it was still a kick ass spot.
Now I find that on lazy Sunday’s I’m spending time in Astoria, most notably at Blackbird’sfor their brunch that includes unlimited…

my friends and i hit up Loving Cup (https://www.thelovincupcafe.com/brunch.html) on N6th the other weekend and they had unlimited blody mary or house beer with brunch (though it's not on their website)
Red Star has unlimited Bloody Mary's or Mimosas on Sat & Sun (I think 12-4?)
I noticed that TBD had a sign outside yesterday advertising all you can drink mimosas for $20, although I did not go in.