Thanks to everyone on the board who has made very helpful comments about Barcelona dining in the past... we tried a number of Chowhound recommendations on a recent trip to this most wonderful city. I thought I would add some of my own comments.
There is quite a bit about the following five places in previous threads, so I will be brief. Comments about some of our own finds are further below.
Cal Pep: Utterly worthy of the praise! Our wait was fairly short, 15 minutes tops. That was for dinner on a Monday night in late February, at about 8:45. Our meal of six good-sized tapas (there are no menus it seems, so we just asked for "una seleccion de especialidades"), four or five beers, dessert and coffee, ran about 65 Eur. Don't miss it.
Talaia Mar: A wonderful meal, but it did not live up to my expectations given the hype around El Bulli. The tasting menu was very exotic (sea urchin soup, tenderloin of kangaroo, frogs legs) and each dish was beautifully prepared, but flavors were occasionally hit and miss (a parfait of sweet vermouth jelly with anchovy cream). The "deconstructed omlette" is their signature dish and is fabulous. The eight-course "menu del degustacion" is 51 Eur per person, and the wine list is very good, with a nice selection of local Catalan wines (the Penedes tempranillo we had--Mas D'Aranyo 1998 Reserva--rivaled the best Riojas I've had at about half the price). Total bill ran about 145 Eur for the two of us.
La Vinya del Senor: A very nice little wine bar directly opposite the church of Santa Maria del Mar. Good selection of wines by the glass, mostly better quality wines, with appropriately higher prices.
Xocoa (on the Carrer Petrixol, just north of Placa del Pi): Terrific pastries, standouts are their ensaimadas and the Pan Quemada (a brioche sprinkled with toasted pine nuts and coarse sugar).
La Boqueria: The most impressive food market I've ever seen. From the quality of the produce to the selection of seafood to the meat counters with every part of every animal you can imagine eating, all was mind boggling. I'd move to Barcelona just to be able to shop here. The best prices we found on jamon iberico (not to be missed, it puts jamon serrano and all but the best Prosciutto di Parma to shame) were here at la Boqueria, but still expect to pay 50-80 Eur/kilo (100 grams was a good amount for two people to share and enjoy... it's very intense stuff).
And now some (I think) previously unmentioned chowhound destinations:
Bar Irati (Carrer del Cardenal Casanes, 15-17; just east of La Rambla, near the Placa del Pi): This was the first (I'm told) of the now-common Basque tapas bars that have popped up in the last few years in Barcelona. The whole bar is lined with big plates of pinxos--Basque tapas, each on a slice of baguette and speared with a toothpick. The pinxos range from fresh anchovy filets with a little dollop of anchovy cream, to a slice of tortilla (a Spanish fritatta), to small blood sausages with ribbons of roasted red pepper, to slices of fresh salmon with dill. The selection is amazing. Each pinxo costs 1 Eur and you pay by counting up the toothpicks when you are finished. Everyone is drinking beer (order "una canya"--a glass of beer), or Basque cider, or txakoli (pronounced sha-ko-LEE), an unfiltered Basque wine that is young and rough and acidic, fairly light in body and alcohol (about 11%) and is a perfect accompanyment to the pinxos. The traditional Basque circus-act pouring techniques are fun to watch--the cider in particular is poured from a bottle balanced on the bartender's head with one hand into glasses held in the other hand behind the back below waist-level. Irati is always packed, but is also very friendly and you can always squeeze in to the bar. It's a terrific place for an early evening snack to tie you over until dinner at 9:30 or 10. Drinks run about 1.50 Eur. Highly recommended.
La Crema Canela (Passatge Madoz, 6; just at the north end of the Placa Reial): We had already eaten lunch at Taxidermista (right on the Placa Reial), and the lines were too long at Quinze Nits (next door to Taxidermista), so we thought we'd try this stylish little place just off the plaza. It was terrific and amazingly cheap (we saw a group of Americans walking away saying "well how good could it be with prices like that? Let's go somewhere else..." their loss!) especially considering the stylish modern decor and stylish diners. Seems like more of a locals place despite it's location in the heart of the Barri Gotic. The staff spoke virtually no English. Appetizers, which included great salads, a couple soups, and carpaccio, among other choices, ranged from 4-6 Eur. The main courses included a trio of grilled meats over the local pasta "fideus", and a "lasagne" with very thin veal scallopini in place of pasta noodles (a Barcelonan friend confirmed that if you order lasagne in Barcelona, chances are you will get veal scallopini... she could not offer a reason why). Other dishes included seafood offerings, a chicken dish, and a beef steak; all ran 5-8 Eur. The most expensive bottle of wine on the list was 12 or 13 Eur. We had a nice bottle of low-end Rioja for 9 Eur I think. This is not a Catalan restaurant necessarily (no local specialties like Suquet or Bottifara), more Mediterranean with Spanish accents, but all was delicious and the total bill, including dessert and coffee (try a "carjillo"... sort of a catalonian version of Irish coffee with your choice of brandy, whisky, or rum), was 43 Eur.
Mamacafe (Carrer Doctor Dou, 10; a few blocks west of La Rambla, in the northern end of the Raval neighborhood): This was another very cheap, fun restaurant popular with locals. It's not too far from one of the universities and the crowd was young, stylish, left-leaning--very East Village-y in NYC or Mission-y in SF. Our Barcelonan friend took us here on our last night in town. Its cuisine is hard to put your finger on... I started with a tuna tartar with guacamole and then had the chicken curry which came with a grilled calamari (the Catalans love the combination of "mar i muntanya"--the sea and the mountain--in essence, surf and turf). They also had a number of vegetarian offerings, which we did not often see elsewhere. The food was all very good, the risotto was a standout. The desserts were some of the best we had in Barcelona... a small selection of chocolate truffles was outstanding, the honey and almond ice cream was creamy and not too sweet and absolutely delicous, and lastly the fresh fruit selection was perfection. Total bill for four of us ran about 90 Eur.
Escriba (La Rambla, 83): This is one of the very high-end patisseries in town, with three locations. Very delightful truffles and other chocolate creations, as well as a nice cafe area with great croissants, nice ensaimadas, and again, good pan quemada. They also had some small loaves of a sour whole-wheat bread, which we brought home and enjoyed as toast. Good coffee, great atmosphere, very old-Barcelona. A great place for a morning snack.
All in all, Barcelona is a chowhound's playground... so much to see and do and try. We can't wait to go back!