Conversation so far:
What was Danny DeVito's first film?
DeVito played Martini in the 1975 film One Flew Over the Cuckoo's Nest.
What was Danny DeVito's most popular film?
L.A. CONFIDENTIAL (1997) - With a Rotten Tomatoes rating of 99%
Are there any other interesting aspects about Danny DeVito?
DeVito and Michael Shamberg founded Jersey Films.
What documentaries does Danny DeVito like?
He was interviewed in the documentary Revenge of the Electric Car about his interest in and ownership of electric vehicles.
Has Revenge of the Electric Car been succesful?
Revenge of the Electric Car received mostly strong reviews.

Question: What other ventures has he been involved in?
Self-contained rewrite: What other ventures has Danny DeVito been involved in besides Jersey Films?