its gotta be tomtom or garmin, everything else is just shite. i sell these everyday. ive got a tomtom go 500 and a go 710, both have been trouble free, but be aware that the tomtoms are well known to have issues, i.e we get 1 garmin returned to every 3 tomtoms, but we do sell more tomtoms. the downside with the garmins is that the navi screen doesnt give you as much info as the tomtom. just do yourself a favour and dont buy a tomtom one v4. had loads of issues with these so far. the v3 is good tho.