Oh, ack. Hoist on my own pedantry.

I dunno. Cult and indy movies are generally not bad, just weird because they are not mainstream Hollywood thingies. They have solid storylines, good if sometimes low-budget production values, and extremely competent if sometimes idiosyncratic directing. Ginger Snaps--Indy. Brazil--cult. Not at all crappy, either of them (though Ginger Snaps is kinda weird)

Crappy movie that doesn't suck--a movie whose acting, shitty production values, sloppy direction or general weirdness make it crappy, but which has something innately enjoyable, appealing or interesting about it. Evil Dead. They Live. Buckaraoo Banzai. Really deranged sci fi like Killer Clowns from Outer Space. Really egregious but lovable characters, like Shakes the Clown maybe. Pretty much any '70s Made for TV movie.

These categories are kinda wiggly, so I don't want to get into some horrid, hair-splitting discussion about categories. This is one of my favorite tribes, actually, because it's friendly and my netflix queue is full of stuff that people recommend here.