It really isnt bad, it was made with a certain campiness in mind, and I think the film succeeds wonderfully. Great soundtrack, costumes, etc.
Don’t get me wrong; I love everything Harry did and own my own copies of the whole list. But as movies go ------ yeah, they are kinda bad. 
And since you mentioned “the G word” let me add Gorgo to the list.
I never quite recovered enough from the 1974 “Flesh Gordon” to try it.
Just the most godawful mess of a movie. Groucho Marx!(his last film). Jackie Gleason drops acid. Carol Channing warbles the hideously catchy theme song. Plus:
Three Batman villians: Frank Gorshin, Cesar Romero and Burgess Meredith.
Peter Lawford, Mickey Rooney and Frankie Avalon.
This movie is so bad, I’d really like to see it again someday.
Have none of you seen The Room?
I’m surprised that nobody’s mentioned the original Red Dawn. It’s hilariously cheesy.
The opening attack on the high school is priceless, and the “logic” only gets worse from there.
Bringing things into the 21st century, you can’t beat Crank and Crank 2 for sheer so-bad-it’s-amazing-ness.
In fact, I think that I’m going to watch them again.
I literally wet myself at this movie. I was about 6 when it came out, and I went to see it with my older brother. He wouldn’t stop watching to take me to the restroom, so I peed my pants. I’m sure total fright had something to do with it.
It qualifies, on these grounds alone.
Ninja-ed on The Forbidden Zone.
How about Pterodactyl Woman from Beverly Hills? With Beverly D’Angelo. One of two notable films with Brion James that year.
Battle Beyond the Stars. The Magnificent Seven in spaaaace. Strangely not listed in recent lists of Seven Samurai remakes/sequels when the most recent Magnificent Seven film came out. It had Robert Freakin’ Vaughn in it! He was in the original Magnificent Seven, the TV show version and something called The Magnificent Eleven.
What, no votes for The Fifth Element?
And Ringo Starr’s Caveman was not in any sense bad. It was just plain fun.
There are two different cuts of Battle Beyond the Stars out there. One is a TV-safe version, where Sybil Danning, the Space Valkyrie, is clad not quite as revealingly. In the other version, her costume is pretty skimpy.
It helps to watch the film in a theater full of bad-movie fans
Space Valkyrie: I’ll show you how a Valkyrie can go down!
Theater full of fans: Go Down! Go Down!
My number one. Most on my list have been named -
Star Crash (in restored Blu-Ray to appreciate the nuances!)
Giant Claw
Ssssssss!
Ice Pirates
Big Trouble in Little China (pretty good to be on this list, I admit)
Roadhouse
The only alt-cut I ever saw was on network TV many years ago. (Remember when the big networks aired movies every week?)
They cut some of Sybil’s scenes and for ones she had to be in there was a mysterious dark patch covering certain areas. Like part of her chest was in perpetual shadow. Clearly added on, not filmed that way. If there was a TV version film, why didn’t the network use it?*
Fun fact: the SFX were by a newbie called James Cameron. Wonder whatever happened to him.
- Although this does happen. When Animal House first aired on commercial TV, e.g., they bleeped the language in the scene with the horse in the dean’s office. Much later, there was a version where the actors are clearly saying different, cleaner, lines.
Strange Brew
Starts out silly. Gets sillier.
There’s always Suburban Commando, with Hulk Hogan as a space mercenary hunting the bad guys in Levittown suburbia. It has a truly hilarious twist scene on a par with some of the best from Kindergarten Cop… lemme see if it’s on YT… yep. (Sorry for the terrible music and sync…)
Does “Kull the Conqueror” count?
Well, my favorite the my about Zardoz was Arthur Frayne.
Anyone ever see a little bagatelle known as Troll II? 
Or along the same theme “Beer”
Norbecker Lite. For whether you take it in a bottle or in the can.
I put the Trolls down with Critters ------- more a guilty pleasure. 
An earlier thead on the topic turned be on the the awful awesomeness that is Latitude Zero.http://boards.straightdope.com/sdmb/showthread.php?t=496048&highlight=latitude