Ronin...awesome Euro cars being flogged at real speeds and drifting with awesome skill.
To Live and Die In L.A. One of the most legendary chase scenes in filmdom, with one of the first time anyone filmed cars headed the opposite direction on the freeway with a wide lens.
Bullitt - Well known and legendary chase, lasting many minutes, between McQueen's Mustang and the bad buys' Challenger through the streets of San Fran. Listen to McQueen double clutch his ass off.
No Man's Land - Some awesome early Porsche driving scenes through the roads of Cali...and a great long chase sequence with a 911 playing getaway from a Camaro and a Town Car, with tons of mayhem!
Lemans - Some of the greatest race filming ever, with cameras mounted all over the cars and mostly triple digit speeds without sped up film.
The Italian Job - Incredible stunts performed in amazing places, while three Mini Coopers which knocked off an armored car excape Milan by driving through sewers, through malls, down stairs, across dams, etc. Legendary, and the remake is now in post production and soon to debut. But you can't beat the original with Michael Caine, Benny Hill, and Noel Coward.
Bond - Pick one...all of them usually have at least a few sections of the film dedicated to chases and races. One of my favorites would be Dr. No for debuting the franchise with the gorgeous Aston Martin Db series...and View to a Kill will Remy Julienne's stunt crew performing soem amazing feats with Renaults through the streets of Paris (and down a few cliffs).
There's a few to start with!