Um, ok, here goes:
Cool trip. For my trip I started in Rome and ended in Paris, hitting Florence and Venice.
Venice is pretty cool, but there isnt actually much to do except wander around and take in the scenery. Take some day trips out to the islands, Murano and Burano, theyre pretty cool to wander around. If your wanting to be a totaly tourist (like me) and take a gondola ride, then all go together to split costs because its pretty pricey. Venice is pretty well known for crappy accomodation. I stayed in The Venice Fish and do recommend it. Its in an amazing location, reasonably prices because the owner and his girlfriend make breakfast, and dinner (which is really good!) And everyone sits around a main table so its a great way to start a conversation with others. The only downside is it only has 2 bathrooms. I had a pretty good time here though.
And, definitly take note if you do stay there, the directions dont mention that the hostel has its own bridge entrance.
I only stayed 1 night in Florence (plans to go back but ended up staying longer in Venice) and I stayed at the Academy Hostel which was good, very clean, awesome bathrooms. I wasnt a fan of Florence, but that might have to do with the fact that I spent the entire night just wandering around the streets with a brazillian guy stopping only to drink sangria.......But the hostel location is awesome.
The Yellow Hostel in Rome has had some great recommendations. Ive never stayed there though (avoid the Roma Inn, its TINY and incredibly hard to find) There is SO much to do in Rome. Definitly hit the Gelato store is Santa Maria Maggiore Gelateria down Via Cavour. I tihnk its just past the basilica. its the best. I adored Rome, the Colloseum, Trevi fountain (at night its great) Vatican, Piazza Navona etc...Get a map from your hostel, everything is basically in walking distance.I stayed 4 days and only just felt I had seen everything.
In Paris I stayed at the Oops hostel. Its kinda a designer type hostel, and its pretty large. Its in an ok location, but besides the people in my room I found it hard to meet others even in the dining area. I did stumble upon some awesome markets while walking around. Ive always been afraid of taking local transport because I always end up somewhere I dont want to be, but the transport in Paris fantastic! Buses and train are incredibly easy to use.
So those are my hostel recommendations. Ive never been to Switzerland, so cant give advice about that. I flew from Paris - Rome, and took trains in Italy. Any other advice you need just ask. Goodluck with the trip planningm you are going to have an amazing time!
Ive been to: England, France, Italy, Scotland, South Africa, UAE, USA - 14 states inc Hawaii, Vatican City
Currently Working in England
After:Jan 5 - South Africa. Sometime 2012 - Canada!