Whenever the subject of car chases comes up, the one in Bullit is the first one that comes to mind, but the one that still makes me laugh and gasp with amazement every time I see it is the one in the original Italian Job with Michael Caine. All those Minis hurtling through those Italian streets, up that enormous building and into that moving truck, each with a load of gold bullion in the back...it was brilliantly done, just plausible enough and probably was responsible for my first couple of speeding tickets (back when the fine was $40).
"Here's your new Mustangs, boys. You can learn to fly'em on the way to the target. Cheers!" -LTCOL Don Blakeslee, 4th FG CO, February 27th, 1944
My top four in no particular order:
The 1970's version of Gone in 60 Seconds
The Michael Caine version of The Italian Job
Any one of about 40 would do for 5th place.