The Infinite Wrench is the one to catch if you haven't seen it: the rotating short-play format means no two nights are the same set, and the die-roll pricing is a genuine gimmick that lands. The Marsh is walkable from the 16th Street BART station — about six minutes, flat ground. Street parking on Valencia on a Friday is not your friend; there's a parking structure on Heron that's less fought-over than the blocks near Tartine.
If you've got two hours and want the most unusual use of them: Infinite Wrench at 8pm, walk to get a burrito after. It runs tight and gets out on time.