My favorite lunch-time stop on Thursdays downtown is the Farmers' Market. I've been going for years.
Always plenty of good fruits, vegetables and other items (like fresh pesto and pies), but you have to get there early. By 12:30 they have sold out of most of their produce.
The Farmer's Market opens at 11 a.m. and stays open until 3 p.m., although (as mentioned above) there isn't much left after the first hour or so!
The market is WIC certified, which means food stamps are accepted by most of the vendors.
Since there still is no grocery store closer to downtown than on Thomaston Avenue, it's great for downtown residents to be able to buy fresh produce at the market.
When you shop at the Farmer's Market, you are buying local, Connecticut produce. So you're supporting local farmers, and you're buying "green"--buying produce that potentially traveled a shorter distance to get to you, thereby creating less pollution than produce shipped in from out of state.