Fantastic. Thanks for that!
You can't make any good restaurant suggestions, can you?! Want somewhere fairly casual, but with good/traditional food, nice atmosphere, and not a tourist trap. I'd really like to sample some Catalan tapas without having to take pot luck on the quality / authenticity! I know you know your food, so... 
For a good traditional restaurant with great service and nice food, book a table at Casa Leopoldo (you might get lucky if you just turn up) in the Raval district. Not the cheapest but very popular with locals and good for a special occasion. Great wine list too.
Can Culleretes is the oldest restaurant in town and is bloody amazing and pretty reasonable too but you may need to book here as well. Bear in mind most traditional Catalan food is less tapas-based and you will find lots of stews, fish dishes and pasta etc.
For good tapas/pintxos go to Euskal Etxea (Basque) on Carrer de Montcada near the Picasso Museum. Ignore the expensive restaurant at the back, just stay in the front bar and grab the pintxos from the plates as the waitresss walk round. Keep all the cocktail sticks so they can add up your bill at the end.
On the same street is El Xampanyet, a traditional cava/tapas bar. Grab a seat if you can and they will bring you tapas and local cava for very reasonable prices.
Try Bar Celta for Octopus and other Galician delights.
Others worth trying: Casa Agustí (near the Museum of Contempory art) is another great Catalan restaurant. Also, most of the bars in the food markets are very good for tapas.
I may post more when I have a bit more time....
