Well, since LifelinerOne explicitly excluded Barcelona, things are getting a bit difficult.
Smaller, not so wellknown cities: Freiburg im Breisgau, Aix en Provence, Ljiubliana and many Italian cities.
Midsize: How about Vienna with a daytrip to Budapest? Florence? Lisbon? Barcelona?
Big: Rome! Paris! Berlin (?). Edit: Never been to Madrid, but heard only good things. Some say Barcelona's better.
[Edited 2005-01-10 20:21:21]