I like the weird ones. A few examples:
Israel 1987 - Shir Habatlanim https://www.youtube.com/watch?v=BWQdWUnroEk
Germany 1979 - Dschingis Khan https://www.youtube.com/watch?v=eAEUrp2V4ss
Finland 2006 - Hard Rock Hallelujah https://www.youtube.com/watch?v=gAh9NRGNhUU
But out of contest, I really enjoyed love, love, peace, peace from 2016 https://www.youtube.com/watch?v=Cv6tgnx6jTQ <-- but that one is probably only funny if you've followed the contest so you get at least a few of the references.