Since relocating to New York, I haven't quite found a theater hangout as definitive L.A.'s Evidence Room. The Zipper Theatre is certainly on the right track: funky bar, gritty space into which you're encouraged to take your drink, comfy seats repurposed from vans and buses (great idea), and Ars Nova seems to have a pretty cool scene going, as well.
But thanks to former Pasadena Playhouse macher Jayson Raitt, who moved to NY about a month after I did, I've discovered Angus, which is Broadway's post-show hangout of choice. Any night of the week, you won't not see at least someone you recognize there. Last night a gaggle of History Boys were hanging out in the smoking courtyard, girls all over them, like the rock stars they are.
You can also pick up a fair amount of juicy theater gossip. Here's a choice bit I heard last night: The lumbering Shuler Hensley, who plays Tarzan's reluctant adoptive father, the gorilla Kerchak (what is he, a Polish gorilla?), was supposed to deliver a moving speech (SPOILER ALERT) after he's shot by the evil white man. Hensley's reported retort: "I won a Tony. I'm not saying those words." And so there Kerchak lies, lookin' oh so peaceful and serene.