I've always found inspiration in low budget gladiator or ancient history and mythology movies from Italy in the 1950s-1960s. They made dozens of these before the spaghetti western was invented and mostly displaced them.
Here are some full length examples.
Goliath and the Vampires - http://www.youtube.com/watch?v=9bjEf5rQ124
Fire Monsters Against the Son of Hercules - http://www.youtube.com/watch?v=XdPGcC3xYE0
Thor and the Amazon Women - http://www.youtube.com/watch?v=F3NwDfPqI_k
Hercules (the Steve Reeves version) - http://www.youtube.com/watch?v=on2oY44h7R0
Anthar the Invincible - http://www.youtube.com/watch?v=0Dpt-vaxMUk
Giants of Thessaly - http://www.youtube.com/watch?v=v3zApRt-ONg
Sappho, Venus of Lesbos - http://www.youtube.com/watch?v=hz1NZ6mgsyE
But films recognizably within the genre have had wide ranging settings including seventeenth century Russia (The White Warrior), some sort of American Aztec-Inca hybrid culture (Hercules and the Sons of the Sun) and the medieval China of fantasy (Hercules versus the Great Khan).
Why do I find these pictures so amusing?
Partially, it's the same sort of pleasure you get from watching any other sorts of movies that are so bad they're funny. Not all of them are like that -- nominally speaking, good films like Gladiator, Spartacus, Ben-Hur and Clash of the Titans fall within the genre. But the more serious in tone and intention, and the higher the production values, the less likely it is I will watch it over and over again.
Bad dubbing, amateur acting by bodybuilder leads, and terribly low budget special effects make the films more fun for me. But it's the relentless kinkiness that adds special relish to these films. There's something for gay and straight viewers alike.
This is fostered by the bog-standard plot that so many of them had. There will be an evil usurper and a good band of rebels gathered around a noble, rightful ruler. But the usurper will have an evil queen that's the true power behind the throne. She is busty and scantily dressed, to let us know she's dangerous. The evil usurper and queen may be the same person.
Our bare and barrel-chested hero will inevitably be captured by the evil rulers. He's probably done some feats of strength before, wrestled guys in bear suits or thrown prop boulders around. But he will be put to the test by a contrived torture scene which he overcomes by brute strength. The evil queen will find herself rendered quite moist as she watches the hero flex his pecs and biceps. Her lust for Our Hero will undermine the usurper's tyranny and ultimately lead to the triumph of good over evil.
And there will always be some kind of hooch dancing sequence. It's a low budget spectacle. And it lets the viewer know that the evil regime is composed of sensuous pagans with a serious taste for hooch dancing. Sometimes, it's the best thing in the picture.
This is adapted from the intro essay to a DeviantArt group I started.