Letters from Iwo Jima and other "lesser" works

Clint Eastwood filmed Letters from Iwo Jima in his spare time, while waiting to start postproduction on Flags of Our Fathers. Iwo Jima wasn’t even supposed to be released until this year. Now it’s getting more critical acclaim, more awards, and a Best Picture Oscar nomination. Has there been any other instance where an artist received more acclaim for what was originally intended to be the side project?

*Wag the Dog * was a quickie, low-buget side project while Barry Levinson was shooting Sphere.

Wayne Wang’s Blue in the Face was shot in five days because he liked the way the actors improvised in Smoke

The original Little Shop of Horrors was shot in two days (not counting a few reshoots) in order to use some standing sets and actors. Roger Corman (who produced) was famous for doing this sort of thing: Peter Bogdanovich’s Targets was shot because Boris Karloff owed Corman two days’ work (though he worked more because he loved the script) and Bogdanovich was able to do it on the condition that he used stock footage from Corman’s The Terror.

Kinda like that: the street-level footage of the first plane hitting the World Trade Center on 9-11 was filmed by a French film crew doing a documentary on NYC firefighters, IIRC. The footage became much better known for what it ended up showing than it ever would have for its original subject.