I used to watch Dream On when it came out.
I currently don't have a favorite HBO tv show except Banshee on Cinemax but I have some favorite HBO made movies:
"61" about Mickey Mantle and Roger Maris
"Long Gone" about minor league baseball team
"Barbarians at the Gate" about RJR Nabisco buyout
"Tailspin" about Korean airlines plane shot down in Russian air space