That's the thing. Some of them are so bad that they're good. I remember watching some terrible sci-fi flick from the early 70's and the production quality was absolutely crap. I couldn't take my eyes off it, it was train-crash TV.
The other night they had "The Erotic Adventures of the Three Musketeers" with Ron Jeremy and Nina Hartley. That's a top-shelf porn film from the 80's, probably cut... but still on mainstream TV!
Another one they like to repeat a lot is "Apex", a really cheap looking sci-fi film from the 80's. I've seen better acting from fan vids on Youtube, it really is that bad.
"Cargo" however seems to have decent production value and decent suspense (I've seen a clip now).
I'll still go see "Oblivion" when it comes out. Not because it's got Tom Cruise, but because I like "scorched Earth" stories.
And it's got Olga Kurylenko.
I have a thing for Olga Kurylenko.
Mystery Science Theatre 3000, great series from the US that used to take the piss out of bad movies. Basic premise was a guy and two robots are stranded on a space station and forced to watch terrible Sci Fi movies. They ad lib comments and provide some background info, bloody hilarious at times. Like you said soo bad its good.