Going with the way that Messy put the question, I have to assume he's giving the choice of a living, working director.

Who would I have a difficulty with not getting another film from?

I'll go through my top ten list of living directors..

Ridley Scott - After that Russell Crowe makes wine thing, I'm guessing a downward trend. Pass

Steven Spielberg - I like almost all of his movies right up to what I call "the first ending". Then he gets all sentimental and gooey and shoots the whole thing to hell with the "second ending". I'm hoping one day he gets it right. Have to pass here too.

Wim Wenders - Makes my list on the strength of Wings of Desire and Faraway So Close, but his other output is spotty. Pass

Martin Scorsese - I haven't seen a misfire yet, although your mileage may vary.

Paul Thomas Anderson - I haven't seen There Will be Blood yet, but I'm guessing that the future has promise here

Michael Mann - Made Tom Cruise interesting in Collateral. He's rumored to be making a movie with Johnny Depp about Dillinger and Baby Face Nelson. Intriguing

The Coen Brothers - (I count them as a single filmmaker--sue me) No Country For Old Men was brilliant and The Big Lebowski remains one of my alltime favorite films that I haven't remotely figured out.

Tim Burton - Some definite misfires (Charlie & the Chocolate Factory, Planet of the Apes), but some absolute knockouts too (Sleepy Hollow, Big Fish, Beetle Juice, Sweeney Todd). He's going to make a feature length out of Frankenweenie (a short he did for Disney - on the Laserdisc set of Nightmare before xmas) and is rumored to do a version of Alice in Wonderland.

Terry Gilliam - Was shooting The Imaginarium of Doctor Parnassus with Heath Ledger. We'll see what happens. Notorious for problems on the set, running out of money, and making the most visually brilliant films I've ever seen, and I haven't checked out Tideland yet.

Sidney Lumet - A long career, with some flops along the way, but noone makes a courtroom drama like this guy (12 Angry Men, The Verdict, Find Me Guilty, Guilty as Sin)

So who do I go with? Who can I not live without? I've gotta go with Lumet, which surprises me as I generally claim to be a Scorsese-phile. Lumet's body of work is all but unsurpassed amongst directors working in the studio system. Check out his book "Making Movies" sometime. The guy is a class act and I hope he lives another 73 years.

Now if Messy had said "if you could only ever view the work of one director ever again".....that's a lot different. Kurosawa, Hitchcock, Ford, Anthony Mann, Kazan, Welles, Sturges, Minnelli, Hawks, Huston, Capra.....I'm out of breath thinking about it.