My #1, all-time-favorite super-8 brand is Eumig. Specifically the 600D-series: 600d, 605d, 607d, 614d, etc. Why? For several reasons:
I used these projectors a lot in clubs and at dance events. 5 in a row, set at 3 frames/sec. and you don't have to worry for the next couple of hours.
Beware, I never had good luck with the Eumig Mark S (sound projector) series. I always looked for the D!
Well known 16mm. brands includes Ampro, Bauer, Bell & Howell, Bolex, Eiki, Elmo, Keystone, Kodak and Siemens. Browse through all 16mm projectors for sale.
These machines might come in handy if you want to quickly 'skim' through your movies to see what you want to transfer to video or for good old editing purposes. Here you can find super 8mm editors and viewers for sale on eBay.
Did you know that the Japanese company Gakken introduced a brand new dual 8mm. projector in 2008? Thats right! Here is the link to their page: Gakken 8mm projector. Don't expect to much from it, it's more of a toy than a sturdy projector.
In the 1960s and 1970s there were also toy film projectors for kids, like this Fisher Price Movie Viewer.