Travel City Direct are usually very competaive (TCD) ..but they tend to have very mixed reviews.......we could not fault them on our holiday though.

Virgin Holidays can also be competative, if you have the time & inclination to keep checking for when they have offers.

Alot depends on where you are planning to go and to some extent when.

Do you want to have everything pre planned or go at your own pace?

Over the last few years I have done several fly drives, booking the flights and car through a company (BA Way), often booking the first night hotel in advance myself.

Then with a rough route planned, stopped at hotels as I have gone along.

Most of these have been in October though and outside the more popular destinations.

http://www.airline-network.co.uk for me, pretty much unbeatable for flight prices and do excellent car hire too, I have used them many times.

TC