Anna's is ok I suppose, but nothing in Boston/Cambridge comes close to Boca Grande. Very cheap, very good.

For those unfortunate ones who find themselves stuck on the Rt 3 corridor NW of town, the Mambo Grille in downtown Lowell (of all places) is definitely not bad. Not only are the burritos more than passable (though they ought to learn how to drain the beans a lot better), but beer and even limited outdoor seating is available.