Hi Rich, any of the latest TomTom or Navman range are good.
I have a Navman iCN 550 which was top of the range 18 months ago, but a little dated now, still going strong, i mainly bought it for the speed cameras, but nowdays i find i'm relying on it more for directions :roll:
TomTom 510 is a good unit and if you want all the bells and whistles the 910 is the one.
Navman N40i is a very good unit for the money, and N60i is the range topping unit :wink:
Mine has a traffic module, which is good as if there's a problem ahead it automaticly re-routes you. Many of the later units have an updated version of this.