Stone's is very good. TJ's in Ashland if you want a burger on a GREAT patio. It is a dive bar that built the patio for the smokers, so keep that in mind. Bullfinches in Sudbury, more upscale. Franco's on Speen st, natick. Good pizza, decent Italian.
Owen O'Learys on Rte 9 eastbound in Southboro just redid their entire restaurant and they have a fenced-in raised patio off the back. Looks out on Rte 9 but it's still pretty nice. also, Oregon Club in Ashland has a small outdoor patio in the front.