I drove with my parents last summer, and we agreed to do a little sight seeing - so we took about a week (camper van) it was lovely. We came through , stopping on Aires - through the Mont Blanc in to Italy and on to the Ancona ferry. We detoured for a day to see Venice, and chilled for a couple of days in Verona - as my parents had done this before, and loved it. What we generally did was rise very early and drive until lunch which we planned to always be in picturesque towns, for a wander and stretch. (Dijon was nice - but take care in a van some of the underes are low). Drive for a few hours to until we found a place with a nice view for coffee brake - aiming to arrive in for the night early enough to relax ( my day did almost all of the driving). The ferry had been d as camping on deck with hook up which my parents had done the previous year which they said was really nice. Unfortunately when we got on, this was not the case. None of the staff spoke either English or Greek, but it was clear we had to leave our van. With only a few minutes notice it was hard to work out what to take - it was really unpleasant. When my parents returned (without me) they were packed in case this would happen again - it did, so they payed for a room (despite having already paid extra for camping, but the company remained unhelpful and never returned any money. They had a lot of stuff to take back, so made the return journey asap, without getting over tired. The home route took them through Switzerland, which had never been considered before, but they said they would do it again.
I've heard of many routes, it just depends on your priorities (budget, speed, pleasantness). We all rather enjoyed the planning (even though it was just the three of us, the whole family ed in with planning), apart from people here - lonely planet has some nice forums, and even if your going by car - campers forums will give plenty of advice to.