I have many, MANY favorites as B-Movies are a passion of mine, but if I had to recommend a single film I'd say "Star Crash," a low budget Italian made "Star Wars" wanna be from 1979 starring former scream queen/Bond Girl Caroline Munro and a young David Hasselhoff (!! Yes, REALLY!!) in his first major film role. The movie features hilarious dialogue, nonsensical plot, and cheap special effects that must be seen to be believed. It's a sentimental favorite because it was my intro to "B"/exploitation films when I was a kid.