yes...went to Rome, Florence, Naples, and Paris on a family vacation a couple years ago...and I'm going again this summer to London, Pisa, Florence, and Rome with the fam again, then a friend is coming over and we're taking the train up to Amsterdam via Florence, Zurich, and Paris.
It was by far the best vacation I've ever been on, and I can't wait to go back this summer. It's going to be insanely expensive, but I've been saving for a while and pretty much everything I make this summer before I go is going towards this trip. If you get the chance...go. I picked up a guide called 'hanging out in Europe' by frommers this christmas and it's been a big help so far, so check that out too.