Best tapas: Granada, then Almería, Salamanca and Úbeda and maybe other places in Andalucía ...
bars and fiesta I would say Salamanca
Best cultural: during the whole year Barcelona and Madrid. Although there are very interesting punctual things in other places
Music festivals: WOMAD in Cáceres and Las Palmas, Pirineos Sur in Huesca, Benicassim, Espárrago rock, jazz festival of S.Sebastian.....
Theater in Almagro, Mérida ....
Cinema festivals ..San Sebastian, Valladolid ..
...
People, I don't know, some people prefer people from the north, others from the south, they're different