Didn't really see any dedicated thread to this place (though saw it mentioned as rec'd in a few threads), so thought it deserved its own.
Made a weekend trip out to Baltimore the President's Day weekend, and had some great food at Tortilleria Sinaloa (Fell's Point). The place is small and authentic Mexican. We ordered 2 carne asada tacos, a pollo, a carnitas, a chivo (goat) and a pescado taco as well as a quesadilla de pollo. The chivo (special for the day) was great - easily the best I've had outside of LA, and ranking right up there with best of LA. Carne asada was also very good. Carnitas was good, though I tend to favor La Mexicana's which has a little bit more crisp pieces in it. My gf had the pescado and didn't like it (said it tasted fishy - and so I didn't try it as I don't like fish), though others have raved about it. The highlight was the quesadilla though. Used what appeared to be fresh queso blanco, and the chicken was great as well. Came with some pinto beans which were also delicious. Freshly made tortillas were very good. Their salsas were good, but not great. The salsa verde was better tasting, but the roja was spicier.
Really loved this place, and I think I would put it slightly above La Mexicana, which is my current favorite in the DMV (gf still thinks LM is better). Prices were high - even higher than DC, but tacos were pretty good sized. This place is tiny though, and was basically empty at 3pm on President's Day, but I can't imagine it being empty really ever. Highly recommend.