So with a new DCU/He-Man crossover coming soon I thought it would be worth taking a look at the first such crossover, He-Man vs Superman in DC Comics Presents #47.
Our story begins with a brief few couple page intro to He-Man and his world, then the same for Superman, and then we cut to Skeletor trying to break into Castle Greyskull.
Well, this obviously doesn't work, and indeed the resulting magical explosion created a doorway to the DC Universe which Superman goes through. Supes and Skeletor fight for a little while before He-Man shows up. Skeletor uses a magic spell to get Superman to attack He-Man and the two of them duke it out for a bit before the spell wears off. As Superman and He-Man go to gang up on Skeletor he decided to get out of dodge and teleports away. Superman and He-Man shake hands and Superman goes back home through the magical portal.
This was a fun little crossover and it's a shame it wasn't followed up on more back when DC had the He-Man license. A couple of years ago there were DC/Masters of the Universe action figure two packs with Superman and He-Man, Lex Luthor and Skeletor, Aquaman and Mer-Man etc. They were cool but a little pricey. If you ever were a fan of He-Man you would definitely get a kick out of this issue but it's pretty pricey on the back issue market so I would really only suggest a hardcore He-Man fan get it. But with the upcoming six issue DC/Masters crossover mini who knows, maybe DC will reprint this issue. If they do you should definitely check it out.