Tongue in cheek bad... or just bad?

I'm doing some prep for a possible book on 'so bad they're good' movies and am trying to come up with a system to categorise these things, I've found this covers most:

'No budget, no talent, no idea' (Samurai Cop, Miami Connection etc.)
'B-movies gone wrong' (Gymkata, Death Wish 3 etc.)
'Studio catastrophes' (Battlefield Earth, Howard the Duck etc.)

But I'm thinking a 'self-aware' category might be a good idea, somewhere to put stuff like Flash Gordon and Buckaroo Banzai. Although they draw on bad movie themes they do it ironically and/or with self awareness (and they're not actually bad movies). This category could cover anything from Ice Pirates to the Rocky Horror Picture Show. Movies that need to be in the conversation but don't fit normal so-bad-it's-good criteria.

So is Megaforce a straight B movie or a self aware ironic movie? Is it meant to be taken seriously or is it winking at us?

Any views would be much appreciated. And feel free to throw out any suggestions, either for criteria to define these things or any so-bad-it's-good movie you think is essential viewing (I'm ignoring pre-70's movies for now). They just have to be bad but, crucially, not excessively boring. I've come to the conclusion that boring is by far the worst thing a bad movie can be!