What is the best/cheapest with most features?

[cavinsmither]

I am looking to buy a GPS car based unit that is reliable and well made. The basic set of features I would like it to have would include (or upgradeable); in car ac charging abilities and portable with battery charged, mount or some kind, life traffic updates (cheap subscription).

If there are any other features anyone feels I missed feel free to make suggestions. I don't have a need for mp3 player or a radio connection unless it is needed for live traffic conditions.