TomTom is one of the best car GPS. It comes with software and you sign up online to program your GPS.
Garmin is one of the best car GPS systems, yet the functions are limited. If you purchase the NUVI 205, however you get extra high-end additions. The GPS routes your travel for you and it is easy to use. The system will tell you where the closest intersection is also during travel so it is apparent it is designed to help you save money on gas. The features include high-end affordability, faster routing, satellite lock, mapping, intuitive use, yet it does not speak the street names nor does it have a widescreen display.
In comparison, the best car GPS TomTom Go 720 is one of the several brands of this particular system. The TomTom has loads of high-end features, which include user-submitted maps that are updated on MapShare. It is user-friendly and provides you with traffic alerts. Magellan and Garmin GPS systems are said to work better than this TomTom model. The spoken directions are delayed according to reviews and there is some mottled reception.
The TomTom One 130s on the other hand, speaks street names and has ultra-portability. The features are limited though, and there is no widescreen display.
When we think of Magellan, the Maestro 4250-R comes to mind. This is the latest navigation system with a 4.3-inch touch screen. It has the most innovative SiRF Star III Chipset technology with Bluetooth enabler. There is the pre-load NAVTEQ maps complete with US, Canada, and Puerto Rico. Voice command recognition, allows you to say where you want to go. Text-to-Speech is another option. There is also the integrated traffic receiver, etc. thus, this Magellan GPS may be one of the best car GPS systems on the market.
this is the general overview of the three top ones, you may want to visit the site for some more info.