Downtown SF Happy Hour Locations?

[guyinsf]

I'm looking for a new location for my Liquid Brain Trust monthly happy hour. Which locations look the most promising to you?

• 83 Proof (yelp listing)
• Dada SF Studio (yelp listing)
• John Collins (yelp listing)
• Zebulon (yelp listing)

Other suggestions?

Next question... Who wants to explore these bars and scope them out with me? :)