How about Prague? How does that compare to those 2 cities?
Have been there only once for a weekend, must have been 6 years ago. Back then it was dirt cheap, but from what I've heard prices went up when they joined the Euro community (but still cheap if you compare it to Munich *lol*). Nightlife was great, lots of beautiful girls. And also lots of beautiful architecture, slightly preferred Prague compared to Vienna, but just my opinion.
Nightlife in Prague is pretty much up there with Amsterdam, Amsterdam is more expensive (Barcelona even more), but I enjoy great architecture and Barcelona has lots of that and I also prefer Amsterdam over Prague from that point of view.
If I had to rank them, Barcelona would be #1, Amsterdam #2, Sevilla #3 (lacks a bit in the nightlife department), Paris #4, Prague #5. Vienna would probably rank 6th. Liked all those cities, but was a bit disappointed when I went to Venice, also didn't like London so much, Rome was really disappointing, Brussels is flat out ugly in my opinion and Madrid was average at best. Havent been to Scandinavia yet, Copehagen and Stockholm are def. on my list for future trips (as is Lisbon).