If you thought that there could never possibly be anything cool/worth visiting near Union Square, you've clearly never been to an Undie Party or, hello, Cheesecake Factory!!! Adding yet another slammer to the pog case that is Union Square: Golden Gate Tap Room.
There's a Stock Market-Themed Cocktail Bar in Hong Kong
There is seriously an arcade's worth of games scattered around the place, including a token slot machine, billiards, these skee-ball machines, and Simpsons pinball -- the coolest game by a somewhat large Marge-in.
And they've got some great stuff that had been in storage (upstairs is a museum dedicated to the Golden Gate), including this awesome vintage cycle complete with a vaguely creepy face!!... :(