The market is now flooded with many brands and makes of GPS systems with a lot of useful features like audible driving directions, points of interest, color maps, speed camera notification, and a whole lot more.

Some of the earlier models of sat nav systems weren't particularly reliable, but some of the newer releases have certainly advanced and are very reliable. A GPS device uses satellite information to find out the whereabouts of an exact location. Whilst these devices have certainly improved they can still falter for a few reasons. These include tunnels, trees and tall buildings that can block the reception.

GPS systems can vary in what they do and so understandably they vary in price. Some of the basic models will only tell you where you are, whereas more advanced models will give you audible or/and visual turn-by-turn directions. Many systems can also be setup to provide directions according to any number of stop-offs you want to make on your way to the final destination, and to provide the route with less mileage or quickest time.

A few of the best sat nav systems include:

TomTom Go 930 GPS - The TomTom sat nav systems have become well-known in this market, and this particular model is very useful for drivers. It provides historical traffic data and lane guidance to make the driver aware of the best routes.

Garmin Nuvi 880 - This model includes a lot of impressive features and performs reliably. One of the most talked about aspects of the Nuvi line is how well the speech recognition works.

Magellan Maestro - The Maestro delivers accurate directions and an easy-to-use one touch interface.

These of course are only a few models to consider. Take a look at several deals and reviews online to find the best GPS systems within your price range. There are several reputable brands constantly releasing new models, so browse a few retailers to find the model that has the specifications you require.