The Polish sausage ($4.45) at Polka's Sausage & Deli may be one of the best in the city. The casing is crisp, the insides are smoky and juicy, and it's all housed in a wonderful soft onion-studded roll.
'italian sausage' on Serious Eats
You don't visit for Vito & Nick's for a sandwich, but if one of your dining companions just ran a marathon or has a hole in his or her stomach that needs filling, then it is permissible to take a look at the remainder of the menu and order Jason's Favorite ($6.95).
Juicy, peppery, garlicky, translucent slices of tender beef heaped on a split Italian roll is the mainstay at Joe Boston's. But add to that the accompanying snap of a well-nestled mild Italian sausage, and you have a meat-on-meat venture that is less about excess and more about pairing.
Italian sausage is easy enough to find in the case of almost any grocery store. But if you're after a version that's made more masterfully—not overly fine, seasoned with refinement—stop by Bari and buy it fresh or have a sandwich.