I said
None. In the 2 1/2 years I've been in our group, I think 3 or 4 beers total have been consumed. We play every other Friday night after work.
I don't ever recall anyone prohibiting alcohol at the game. We just don't usually do it. All but the host (most always the DM) must drive, some of us 30 or more miles. Frankly I rather enjoy a nice little blast down the highway after the game, usually a bit over the limit.

'Nuf said.
During gaming, I simply like having a clear head, just as I do if I'm programming. For instance, if I'm going to write code at night even if it's recreational, I'll have little to no alcohol with dinner. A little alcohol affects the quality of my thinking. With D&D, I'm not around a table with a bunch of the guys. We're adventurers fighting monsters to the death. It's the most important thing in the world. Yeah, we joke, we eat, we drink water, soda, or coffee, but the gaming is deadly serious.
When I get home from a gaming night, I'll unwind with a spot of something - sake, bourbon, or scotch, savoring the adventure and looking forward to the next gaming session.