I'm sure The Wire is just as compulsively watchable, and I look forward to seeing that in its entirety (all in one go some weekend--hopefully soon), but Le Samourai rules too, and it's a bit more off the beaten path for a lot of viewers. Melville made vivid, highly stylized crime films with sparse dialogue. They look fucking fabulous (see Le Cercle Rouge for one of the best examples of this), and his writing is good too. He dealt a lot with morality, often depicting very dignified and intelligent criminals, and police with varying degrees of intergrity. Melville didn't even consider himself an artist but I'll be damned if his movies don't smack of greatness. Some well-known trivia: He was a Frenchman obsessed with america, who wore a stetson hat and drove American cars almost exclusively. He took his surname from Herman Melville and was a very stylish director who had his characters' outfits made from only the best fabrics. Melville was Alain Delon's favorite collaborater (they made at least a few movies together), and he played the philosopher guy in Godard's Breathless, the guy who says his ultimate goal is to become immortal and then to die. He once said he felt very fortunate to have been alive during WWII and his film about the French Resistance, the recently re-released Army of Shadows, is serious as cancer in its depiction of the time he lived though, fighting underground in occupied France. Lastly, Melville's early film Bob le Falmbeur inspired the original Ocean's 11 (and several other "robbery flicks" at the time). Ocean's 11 was then of course remade a little while back and spawned a couple, presumably just as cheesy sequels.
He's a hard guy not to like the more you learn about him:
Who could resist a chic, mod-y crime movie?