Tuscany, Italy; London, England; or Paris, France for a 20 year old female to go to for study abroad. ?

This summer (June or July) I will be doing a study abroad through my college. Mon through Thurs we will have cles and field trips to tourist sites (museums, plays, ect). Fri through Sun will be open for me to do what ever. For a 20 year old female who likes to have fun.... where should I do my study abroad... tuscany, italy; paris, france; or london, england. I want some entertainment on my days off for i will see all the educational sites mon through thurs. I like music and concerts and dancing so i want to go to a place with some nightly entertainment and shops.