Well there were the BBC Dirk Gently TV series starring Stephen Mangan . Although loosely based, personally I think they are grossly under-rated and probably the best small/large screen representation of DNA's work
I enjoyed those, too. Stephen Mangan was a perfect Dirk - pretty much exactly how I imagined him when reading the books.
There's also a Netflix "Dirk Gently" that is nothing to do with anything DNA did. Still quite entertaining and a suitably odd plot, but only Dirk Gently by name.