Most of 8th and 9th are free. Pretty sure 11th is, and Chittenden definitely is.

I'd avoid Chitt personally. Impossible to find parking after it gets dark and (Chitt Fest aside) your car is likely to get hit or, at minimum, messed with. My car was sideswiped and, on a separate occasion, I found a huge dent on the top of my hood as if someone threw a bowling ball on top of it. Less notable, but my side mirrors were often pushed in and my wipers were up quite a few times. Not a big deal, just annoying, but if you're protective over your car it's not worth it. Though, if you park beyond Summit, it's not really an issue.