Great stuff - to think they get paid to do that!!!
Probably the ultimate low level plane is the trusty old Buccaneer - Funnily enough it is called the Banana Jet - one for Cookee!!! With a full weapons load it is still the fastest low level plane around - shame it's been retired.
"Clean" the Tornado is probably the fastest but one thing people don't realise is the hammering the pilots get when they go low - pretty much like in a Rib really!!! The British aircraft tend to give the best rides - some of the Yank and Russian planes are impossible to fly low for very long without injuring the crew!!!