Batman with Robin the Boy Wonder, to my knowledge, has had no DVD release, sadly. I only knew of it because of a five episode VHS from 1992.
Captain N has the whole series in a boxset. Apparently it's missing some stuff, though. Don't ask me!
Captain Scarlet has it's entire series out on DVD in both the UK and US.
There's a few five episode DVDs for The Real Ghostbusters, but a complete series is out, I hear!
Hulk Hogan's Rock 'n' Wrestling exists only as ancient VHS tapes
The Incredible Crash Dummies, unfortunately, only had a VHS release back in 1993, and I can't imagine it appearing again anytime soon. There's no downloads on the internet, either! Only a low quality YouTube video which is my source for the images. Lame.
Sonic Underground's all out on DVD, in both individual volumes and as a boxset. I think. I don't care to check!
Street Sharks only has crappy two episode volumes that nobody would willingly buy, but any existent fan club out there would suggest you do so in a feeble attempt to get the whole series out. If only.
Teenage Mutant Ninja Turtles has seasons released, and just from a quick check on Amazon, season 6 is out. How about that!
See Transformers for that kettle of fish. Scramble City is generally on the movie or anime DVDs.