Had a great time in Barcelona... I stayed in the south of the city in a seaside resort in the city of Casteldefells... THe train ride to the town center was 20 minutes and as usual in a european city the public transport system is very efficient.
Barcelona is a party town !! Olympic port is a great plac to start off with lots of restuarants and at 12:30 am or so you see the clubs and bars starting to pack up. The people in Barcelona are out and about late night every night even week nights !!
Right next to the olympic port you have old town which will get you to the awesome cathedral :
Too bad while i was there it was under renovation and all you could see was scafollding
Then you will reach Les Ramblas which i would say is the equivlant of CHamps Elysee in Paris. Very lively with lots of restuarants, pubs, street performers...
The weather was amazing it was 21-25 sunny and crisp. If you want to party and have a good time i absolutely recommend Barcelona !