We will be up for a few days this weekend staying on Union Square. We have reservations for Ideale (my wife loves a good carbonara) and I plan on walking over to Cafe Mason for breakfast early one morning (thanks to RW Orange for the Cafe Mason mention in a past SF thread).
We are looking for another fairly casual dinner place, and I wondered how Serpentine is for dinner? I noticed it was recommended for brunch. The menu looks fine and the photos of the restaurant make it look inviting. We'll cab it for dinner so other recommendations don't necessarily have to be in close proximity to Union Square. Just not too expensive (something on the order of $35 pp for dinner without drinks, tax or tip).
Thanks in advance for any other suggestions.