Which one is good as a base : Tiberias or Nazareth

Neither of these cities is a good base for touring the Galilee region IMHO. A huge part of the experience in touring Galilee is to experience its RURAL nature. I don't suggest staying in either these of these cities. Instead, consider using one of our wonderful kibbutz guesthouses as your base for touring. Nof Ginosar on the shores of the Sea of Galilee just north of Tiberias is a great choice. Another good choice would be the Kibbutz Lavi hotel if you plan on staying during the week and not on the Jewish Sabbath (Friday & Saturday).

I agree with #1 about not using either city as a base. He lists 2 very good hotel options. However, if you want something a little cheaper, stay at a kibbutz or moshav "zimmer" (basically a B&B).

The fact that you are speaking of bus networks tells me you are NOT renting a car. That means, staying in any place suggested by davetheguide is a terrible idea. Transportation is poor enough in the north. His ideas would only make it worse. Stay in Tiberias. It is not a dirty run down city. It is a city that is very incorrectly described by many and you will be pleasantly surprised.

BTW as you take buses it may help if you knew the Hebrew names for things. Tiberias is Ti-vair-ee-uh and the sea of Galilee is the Kinneret in Hebrew.

I too would suggest sleeping in delightful Tiberius, in the evening you have a range of hotels, hostels, cafes and restaurants for all budgets, Tiberius also has an evening free sound and light show on the harbour edge. It's a no brainer to be isolated on a moshav or kibbutz and have to pay for accommodation which may not suit your pocket, especially if you are reliant on public transport. But they are fine if you have hired a car and are mobile. Allow me to suggest; http://www.hostelworld.com/hosteldetails.php/Aviv-Hostel/Tiberias/43574?source=googleadwordshostelsbyname&kid=560954&aid=2&gclid=CMmCnMfM5LICFQ_MtAodoUIAPg
If you are paying for a private room, ask for a ''lakeside view''. Also check out the Tiberius information office, for a wealth of free info and top-tips, from a local woman.

Nazareth is a half day trip by public bus via Cana (service number 431 and it takes approx 45 minutes) from Tiberius bus station, and the Nazareth street markets will be open in the day time.

You didn't explicitly indicate that you are not interested or unable to rent a car. If you are relying solely on public transportation, stay in Tiberias, but beware of the fact that you are going to have a very difficult time touring the Galilee region using public buses.

If you are able to rent a car for Galiee and the Golan Heights, by all means do it. And if you do have that rental car, I strongly suggest not staying in Tiberias, but rather in rural accommodations.