Le Mans. Papillon. The Getaway. The Great Escape. The Blob. There are plenty more, and most all of them are great, but I say his best movie was Bullitt. Released in 1968, it's about San Francisco cop Lieutenant Frank Bullitt (McQueen) trying to get to the bottom of a mob hit. There are some minor problems with the movie, such as the victim of that hit facilitating his own murder in a manner so spectacularly stupid that fans have had to come up with complex theories to explain it. But overall it's damn good, so do yourself a favor and see it if you haven't.
Bullitt perfectly demonstrates why McQueen remains the King of Cool, which may seem odd because he does a lot of things in the movie that are decidedly uncool (or, at least, not the sort of thing modern movies insist cool guys spend their time doing). He sleeps in pajamas. He goes grocery shopping and picks up an armful of TV dinners, and doesn't even shoot a bad guy through a glass freezer door in the process. Hell, he doesn't shoot anyone until the end of the movie, and then it's with a small revolver and not a wrist-breaking Desert Eagle or similar hand cannon. During the historic car chase, he isn't decked out in leather and Ray-Bans. He's wearing a turtleneck. And afterward he has to drive his girlfriend's VW Bug.
Movie tough guys simply don't do these things today. There's a good reason: It's easy to look cool with quick editing and flashy gear, but the mundanity of day-to-day living breaks the illusion. Usually. But not with McQueen. McQueen is elementally, irreducibly cool.
That's not to say there aren't other cool things in Bullitt. There's flute-centric jazz, Simon Oakland (Kolchak's editor), and, of course, that beautiful '68 fastback Mustang. Rumor has it that scientists were afraid that combining McQueen and that Mustang would create a situation so awesome that God would crush the earth trying to high-five the director.
The world is definitely a less cool place without Steve McQueen. We all have some work to do to compensate, and there's no better time to start than his birthday. McQueen wasn't cool in a glossy, shallow way, but in a fearless and grounded approach to the adventure that life should be. So squint, grin, and raise a glass to the McQueen in all of us.
And if you've got a turtleneck, rock it.