the devil bat (1940)

aka Killer Bats.
"Not so funny when it's your own jugular vein that's in danger. Is it, doc?"
Scientist Dr. Carruthers (Bela Lugosi) has a grudge against his employers, believing he's been stiffed by them and plots his revenge. The obvious solution is to develop a way of enlarging bats and training them to kill. But reporter Johnny Layton (Dave O'Brien) is on his trail.
An entire city of secret laboratories, rubber bats on strings and Bela Lugosi emoting furiously, whats not to like?

the sweeney 2 (1978)

"No Dogs. The last time we had dogs, they bit every man present but the villains."
The second TV spin-off sees Regan (John Thaw) and Carter (Dennis Waterman) after a team of blaggers. Things get complicated due the criminals living in Malta and only jetting in for the bank jobs.
A gritty drama, that manages to maintain the look and feel of the TV series, whilst expanding the story out of the usual London manors.

the sweeney (1977)

"All right, Tinkerbell. You're nicked!"
Hard nosed detective Regan (John Thaw) gets mixed up with political corruption, which sees him framed for drunk-driving and suspended. Can he conduct an investigation from outside of the squad, and get to the real villan of the piece.
Continues the grittiness of the TV series, producing an entertaining drama with the usual pathos and swearing.