Sal's is shockingly good for such a dive. I mean, they give Pizza Sola some serious competition in my opinion!
Don't be fooled by the dingy interior and decor. A slice at Sal's will put you in pizza heaven, all for $3! These are New-York style slices - in other words, larger than life and all built on a fairly thin crust. I've only ever gotten the cheese here and it's always been fantastic (that's how to judge a good pizzeria, right?). Their twilight hours provide ample room for drunk dining and bad (but delicious) diet decisions. Only downside to that is dealing with the obnoxious clientele at that hour.
Sal himself is also super nice, in that New-Yorker-running-a-pizza-shop kind of way. While they could use a bit of housekeeping, their pizza is pretty darn good.