Big 1-room apartment, quite central (within the historical center of Bologna). Quite inexpensive for Bologna but also spacious for one person (OK for two young people).
The host was very responsive, friendly and flexible with checkin and checkout (had to book last-minute and he was impressively quick).
Only downside: the entrance faces the street, but it's definitley not a busy one. However, you can sometimes hear someone talking or a car passing. I could still sleep in, though :)