Lucerne. As far as cities go this is probably what you are looking for.
Zurich, meh. Expensive, loud, lots of people (perhaps too many). If you haven't seen NY or Frankfurt then sure, visit Zurich to get that big-city feel. Just instead of a big American or German city it is a big Swiss city. Some great bars, good music venues, museums even. Still a big city.
I enjoy my time in Lucerne more. A good place to both see things (the lake and the boats thereon, the Lion, the transportation museum--that rocks, the peaks around the lakes, the bridges, the night and street life that is vibrant) and relax and recharge.
Also, the badges/stickers for driving in Switzerland--get them at the border. They pretty much look at your car, inform you that you do not have one (if you don't), and tell you how much you are going to have to pay them (right then) to get one that they then affix to your car window.