Could anyone rec. hostels or decent, inexpensive hotels in Barcelona, Rome, or Venice?

I spent a week at Hotel Principal in Barcelona last December and loved it. Very reasonable, clean, comfortable, courteous service, free internet access and an excellent breakfast buffet included in the rate. Close to Las Ramblas. Charming neighborhood which I could view from my little balcony with an interesting youth hostel across the street and a friendly little outdoor cafe at the corner less than a block away. Here's a link to their website:
www.hotelprincipal.es

The Hostal Opera is clean, quiet, and cheap.

I stayed there last year. It is close to Las Ramblas, beside the opera house.

hostal opera