re: Italy (Rome/Florence/Venice) eating recommendations?

I really like Buca Mario in Florence. The food is great, the wine list is fairly priced, and in spite of the fact that they'll give you a "Buca Mario" apron after your meal, it's a great experience. If you want an authentic Bistecca Fiorentina, go to Sostanza. It's a small place, I think they only do two seatings a night, most of which are at a huge community table. Menu is simple but it's a fabulous experience. You'll need a reservation fa sho. Going in a different direction, Cantinetta Antinori and dei Frescobaldi are restaurants owned by the Antioris and the Frescobaldis respectively, probably the two most prominent wine families in Italy. You might expect them to be tourist traps, but they're actually very high quality restaurants with the nice benefit of offering virtually every wine made by their respective wineries, by the glass and at reasonable prices.

Rome is a tough food city, at least I think so. I don't know that I've ever had a great meal there. ETA: I do like Al Bric, which I've been to several times. It's fairly wine centric, but the food is very good.

I hate Venice, so I'm no help there.