Id say these 3 are the best at gettin nice and low
especially Dale 'Snort' Snodgrass (he flies the stang)
http://www.airshowbuzz.com/videos/view.php?v=e801adb4
here is Snort doin a bunch of super low passes in his Sabre
http://www.airshowbuzz.com/videos/view.php?v=2e9145bd
the pass at 0:45 is the lowest ive ever seen him go