Bela Olhao Portuguese Sardines ($3)
Sardines are the most underrated canned seafood, in my opinion. I've found this particular brand makes the best canned seafood. I'm particularly in love with the lemon sardines (and octopus, but that's another tale). I often crack open the can and eat the sardines solo for a quick, extra-filling snack, but they are also magnificient in this puttanesca sauce.