What is the best super-8 camera? Well of course the one you have with you! No kidding, it's all about what you do with it and want to film. But of course there are some very good high-end cameras, a lot of decent cameras, and a whole bunch that might be better avoided. I say, definitely avoid the Nizo Integral cameras, I never had a single one that actually worked. I recommend a Nizo 481, 561 or 801 if you have a modest budget and you don't need to record sound with an external recorder.
First of all: what do you want to do with your camera, film indoors or mainly outdoors? Sport events, fast camera work or will it be on a tripod a lot? Most cameras will shoot at multiple speeds but the cheaper ones tend to only have the 18 fps. option. At this speed, your precious film cartridge with 50 ft. (15 mt.) of film will last around 3 min. and 20 sec. Also good in low light conditions since the slower shutter speed will let more light through. Most sound cameras have 24 fps. which means you can film aprox. 2 min. and 30 sec. with one cartridge.
If you want to process your own films, look out for a movie developing tank.