Thanks to everyone who has posted about Puerto Rico - the research I did on this board paid off, and I found some other places well worth a mention.
Casita Blanca (Santurce/San Juan): Mentioned quite a bit here, with good reason! We were actually not that hungry, but polished our plates, because it was such soulfully delicious food. The filete de mero (grouper filet) was very flavorful and flaky, the picadillo de carne (ground beef with sofrito seasonings) was addictive, and the carne frita (fried pork chunks) was moist and crisp and very porky. The bacalaitos (codfish fritters) were thin and fine, but not my favorite. The sangria de mavi was delicious, and their house made pique (hot sauce) and herbed vinegar were fantastic. I loved that they held the stacks of napkins down with potatoes and onions! I loved this place, and will return whenever I can. Thanks for pointing me to it, chowhounds!
Bebo's Cafe (Santurce/San Juan): I found my asopao here...a rice soup flavored with sofrito, with juicy pieces of chicken. It was very good. Also had mofongo de carrucho (conch) with a garlic sauce which was also very, very good - the mofongo was loosely packed, with big chunks - just the way I like it. This meal was a choice between this place and Casa Dante, and I chose Bebo's Cafe because of the lechon we had at their sister place. Disappointed that they didn't have lechon/pernil (roasted pork with crispy skin) but the chuleta kan kan (crazy huge cross section chop) was good.
Bebo's BBQ (Carolina): excellent lechon and the ribs were amazing. Morcilla (blood sausage) was good, and the chicken was moist and flavorful. The arroz con gandules (rice with pigeon peas) was fine, but the yuca with onion and garlic was incredible. Cheap, delicious, long lines, but worth it!
Kasalta (Santurce/San Juan): Medianoche (pressed sandwich) was great, but I really loved the marinated octopus salad, and the baby conch salad.
Cafeteria Mallorca (Old San Juan): Delicious pressed breakfast sandwiches on mallorcas (sweet bread) and excellent coffee.
El Parilla (Loiza): This is a little mom and pop place in a non-touristy town. We ordered the ubiquitous chillo entero frito (whole fried red snapper) and it was phenomenal - crispy skin, moist and flaky flesh, with an amazing garlic herb sauce and fresh onion slivers. My mouth is watering just thinking about it! Their mofongo was too dense and smooth for my liking, but their habichuelas guisadas (red beans cooked with sofrito) were so good I ordered a pint to bring back home - a flavor wallop! These beans were one of the best tastes of the trip. Less successful were the tostones (double fried smashed green plantains) with lobster - the lobster was flavorless, rubbery and dry. Still, if in Loiza, I recommend this place.
In Loiza, we had mofongo from a food truck right across from the Shell station, and it was terrific, with strips of beef and a great garlic sauce. We got some pan de agua (puerto rican white bread loaf) and a quesito (puff pastry with sweet cheese) at Lirey's bakery - both good, but not destination-worthy. My favorite breakfast in PR is pan de agua smeared with the huge, juicy, local avocados...I got mine at a little store/shack called El Cocotero, which was a mini-emporium of Puerto Rican delights, including mavi (the mildly alcoholic, fizzy sweet drink of fermented mavi-tree bark - SO good), all kinds of sweets, fruits, canned goods, and coco frio, the fresh green coconut with the top chopped off so you can drink the water.
In Rio Grande, on the way to El Yunque Rainforest, we stopped for breakfast at La Familia Bakery #2. I think yelpers have put this little place on the map, because there were plenty of tourists as well as locals, but it didn't matter because the food was great. We had a revotillo completo (scrambled eggs with ham, onions, cheese and tomatoes) which was good, and the breakfast sandwich of egg, ham and cheese on pan sobao (soft, sweet bread that is their specialty) was excellent. We split a quesito here, and it was sooooooo good that we ordered three to go - had them for our final breakfast and they were insanely good. I would seek these out again.
In Luquillo, we of course stopped at the kioskos. So, when I came here years ago, I don't remember the restaurant-style ones like La Parilla and El Jefe burger...I remember a bunch of fritura (fried snacks) stands - there are still some, but the whole thing seems so much more developed and tourist-centered now. That's the bad news - the good news is that with a little picking and choosing, we had a fantastic experience. First piece of advice - look for the little awnings in the parking area. At one, we had excellent and cheap oysters and clams on the half shell, served with a watery homemade pique that was perfect. At another, we had superb pinchos de cerdo (pork chunks skewered and grilled) that were astoundingly delicious, served with a tangy, sweetish sauce. We also had good bacalaitos and a mind-blowing alcapurria de jueyes (plantain batter fritter filled with crab and sofrito) from La Roca Taina - a kiosk on the eastern end of the strip.
In Piñones we found a kiosko experience more similar to what I remember at Luquillo years ago. This is a strip of beach (west of Loiza, east of San Juan) we bypassed the line at Kiosko El Boricua and found a beautiful little cluster of shacks, each with a wood fire powering their cookery. This was the best bacalaito of the trip - HUGE and delicious. Alcapurria de jueyes was a close second to La Roca Taina. We had a great arepa with bacalao guisado (salt cod cooked in sofrito) and a wonderful pionono, which is a mini version of the piñón - a casserole of sweet plantains and ground beef.
I'm miserable that I cannot remember the name of the little roadside trailer near the Playa Seven Seas near Fajardo. The arepa with marinated octopus was incredible - we were fighting for the last pieces. The pastelillos (fried turnovers) - one of ground beef, one of carrucho - were also very good.
Also forgot the name of the little house-front fritura place in Naguabo. We got the pastelillo de chapin - fish cooked with sofrito. The fish mixture was absolutely delicious, but there was like a teaspoonful in the hand-sized pastry. I think they must do a booming business, though, because she asked if I wanted a box of frozen ones, or one of the freshly fried ones.
I think that's it, except for one last food memory. The mangoes in PR are amazing, and the best place to eat one is at the beach, in the water, where you don't have to worry about the sticky juices, because the water washes it away. The salt water on your lips and skin makes the mango taste insanely sweet, and if you are lucky, when you are done, a school of fish will be swimming in and out of your legs.
Planning my next trip already....