None of those touch my MIL's lemon shrimp jello - although the tuna jello comes very close. The rice crispie treat Christmas tree made with cornflakes is actually really good - especially with red hots as decoration - I don't understand why it was on the list. People make similar things all the time nowadays so it's neither vintage nor horrifying.
Before I opened the link, I thought the shrimp tree was some Jello concoction from hell. I thought the cornflake tree looked pretty good, too. I remember eating those kinds of treats every once in awhile as a child. It's really the only way I can stand cornflakes. :)