oy, um... I trying to remember off the top of my head -- these are the things jumping out at me:
Lisbon -
the Chinese Ballroom (hit the mother of pearl star buzzer and a man in a tux peers at you through the peep hole and decides whether to let you in or not.) it was seriously the coolest bar I have ever been too - all the rooms are a different theme of antiques - toy soldiers and military in one, roseville vases in another, etc. and they have absinthe on the menu. not sure if it's there anymore, maybe a restaurant in the elevated section can tell you (can't remember what the elevated section is called!)
the port institute with a binder the size of a telephone book too select your port from
not between Porto and Lisbon, but Evora not too far away from Lisbon, and is a very very cool world heritage site and has a capella dos ossos (super freaky!)
I have not been to Porto (yet!)
Madrid -
Museo del Prado - Guernica is there among many other Picasso, Miro, and Velazquez
pickpockets, pickpockets, and more pickpockets
tapas bars
rose garden
Seville -
the cigar factory where the woman in the opera Carmen worked
the tile work at Plaza de España
again, all just top of my head... if I think of more, I'll post!
__________________
"Fashion can be bought. Style one must possess." ~ Edna Woolman Chase
Ooh, I love Spain! Here are some of my Madrid faves:
-As D mentioned, Museu del Prado is obviously the biggie among art museums, but I also really love more modern art, so the Centro de Arte Reina Sofía is a must see for me, too (it has Picasso's Guernica among many other great pieces)
-If you have time for a day-trip, El Escorial is definitely worth a visit. I enjoyed going to El Escorial because it was quick and easy to get to on the train and offered a fun chance to see what some of the Spanish countryside looked like.
-Madrid's nightlife and food are amazing, so you should be sure to reserve at least one evening to stay up really late and jump around to different tapas bars just like the natives do.
I will be so jealous when you are dining on Menus del Dia.
Hey, gingembre1, I'm going to Spain next week, too, and I'll be in Madrid for part of the trip. I have Madrid fresh in my mind because I've been reading guidebooks all week -- I was there before, but it's been six years, so I needed to refresh my memory.
Anyway, in Madrid, I recommend Palacio Real, the Spanish royal palace, which is so decadent and over-the-top it has to be seen to be believed (unfortunately, you can't take pics inside). It's fun to get bread, cheese, and some jamon serrano for a picnic in the lovely Parque Retiro, weather permitting. We plan on doing El Escorial for a day trip, too.
If you're interested, El Botin in Madrid near the Plaza Mayor claims to be the world's oldest restaurant still in operation: www.casabotin.com
In Seville, the cathedral is definitely worth seeing. Also check out Giralda, the bell tower at the cathedral -- you can climb to the top (tiring, but worth it) and get some great scenic pics of the city. The gardens of the Alcazar of Seville are lovely, too. Have fun!