You can find info about all the bike shops in Milan and vicinity at http://www.bicimilano.it/negozi.htm

I would recommend:
1) Bicimania in Lissone - pricey but well assorted
2) Guerciotti - very good service and mechanics
3) Cicli Ambrosini in Varese (25 miles from Milan) - good prices (http://www.cicliambrosini.com/)

You may also check out bike factories with excellent showrooms:
- Colnago in Cambiago (worth a visit, lots of racing history)
- De Rosa in Cusano Milanino
- Rossignoli in Milan

I am not familiar with bike shops in other towns.
I hope this can help.
Jacopo

G. Bianchi in Florence

There's a really nice shop outside of Sienna, can't remember the name.

Bici Centre in Cagliari, Sardegna. They also make their own frames under the Pistidda brand.

Rabottini in Abruzzo.

There is a great place in San Remo called DanyMark Cycling. The owners are Marco and Danilo. Danilo was the regional champion in mountain biking for 2003 and 2004. They took me for a ride up the Cipressa and Poggio climbs of the Milano-San Remo classic....great guys!!!!

Here is the info.:
Corso Cavallotti 158
San Remo (IM)
tel. 0184 50.15.49
www.danymark.com