Hello!
I would recommend Portugal, Lisbon. It is still very nice temperature here in October and Lisbon is a very interesting city, full of history. You can do anything there: eat delicious food (and not very expensive), drink good local wine, spent hours and hours just walking around the city, have a coffee in small cafes, dance all night and much more.
You can really have a good experience without spending too much. If you would rent an apartment or hostel, it can be really cheap (i have been renting a very nice place in a city center old part of Lisbon - Alfama, cheap apartment through -- removed --). Alfama is a very cozy area, not far from Castelo São Jorge (10-15 minutes walking), from where you can enjoy the panoramic view of Lisbon.
If you going to decide to come to Lisbon, i can help you with few more advices..