Navigation system for car

I like Garmin, but it I'm sure the other brands are fine too. You might want to go to a store that sells multiple brands to compare them for yourself. I would advise you to also take a road map. It is not a good idea to rely solely on a GPS.

This question has been covered already, which you'll see if you do a search for this site. Seems like each brand has its fans. No matter which you choose, I believe it is best to spend more and get the preloaded Euro maps, rather than buy the least expensive GPS and then have to purchase and download the country to which you are traveling. If you look online on the TomTom site, you can easily see which have the US and Europe. We have 2 TomToms and they have been great in the car, but the battery for walking around has been less satisfactory over the years, so bought a new battery.
There are some makes that are better for walking than driving. I love having one.

I particularly like TomTom because of it Live Traffic functions. They also have an excellent iPhone app that sells for € 59 all Western Europe or € 39 each major country.

I've owned several and prefer the new Garmins. Buy it and get used to it driving around your hometown. Go on ebay and buy a used chip with the Europe maps for half the price of new. Sell it when you get back for the same price. Keep the GPS which is great at home also.

I bought a Garmin 275 for our trip to Italy, which we are currently on. Works pretty well in Tuscany. Accurate, does not get confused. If possible, you want to keep the GPS on until you stop driving so that it knows where it is before you turn off the power. If you do that, it wakes up quickly on power on. If you turn it off a mile before you park the car, it takes the darn thing 5 minutes to figure out where it is. While it is good in the country side, it's more problematic in the cities. Narrow streets and 4 story buildings make for a poor view of the sky, so the GPS often loses satellite coverage in towns. For that reason, a good map and even a cheap compass (so you know where north is...) are handy. I read the thing about the compass, but didn't follow the advice. You don't need a complicated one, just a keyfob compass will do.

A compass will get dorked up by the magnetic field of the car. Most GPSs have a compass feature (either an arrow or numerals). You may have to fiddle with the settings to make it part of the display. It seems to continue working a tad longer than the map position indicator when the signal is blocked - - I have no idea why.

I started with a TomTom and have had no reason to change. I bought my first because it's made in Europe but liked it well enough for use in the US and Canada that I've stuck with the brand. Garmins are also highly rated - I doubt I would go with something other than one of those two.