Locals pack into this colorful restaurant at lunchtime for down-home comida criolla, the traditional Puerto Rican cooking that pulls from the island's Spanish, African, and Indian heritage. Ignore the slightly cheesy décor—e.g. ceramic conquistador plaques—and instead focus on the tostones (fried plantains) and the mofongo (mashed fried green plantains with red snapper), which are easily the best in Old San Juan. Everything's cooked to order by the owner's wife, Alda, and the portions are big enough that you might not need dinner.
Tip: Since the local crowds tend to be thick around noon, plan to show up around 2 p.m.; you won't have to wait for a table.