Philips Navigator BritainRRP £19.99
Best of the web £12.99 at amazon.co.uk
Overall
Performance 
With the majority of mapping at a scale of 1:100,000, this atlas is so detailed you could do a road rally along farm tracks with it. Despite this, the atlas manages to remain uncluttered. Better still are the town maps, which are highly detailed and even have their own indexes of road names and grid references.
Ease of operation 
Everything is clearly labelled, making it easy to find everything you need. Its near-A4 sized pages strike a good balance between information and practicality. Speed camera locations are marked with the speed limit. The plastic cover is durable, and there's no gaping seam between its glued pages.
Buying 
If you shop around online, you'll hammer the list price down to a more reasonable level, and bag yourself a great atlas for sensible money.
Quality 
This is a no-nonsense atlas, so, although it does contain plenty of special features, the
focus is on providing clear, detailed mapping. It's well indexed, easy to navigate and the only mild complaint is that the paper feels a little thin, and could rip.
Special features 
The town, airport and port maps are the crown jewels and the best we've seen, providing huge levels of detail. Other information is fairly standard, and includes route-planning maps, mobile speed camera locations and distance tables.