Let's talk Instax 210! It's my favorite instant film camera right now. It's inexpensive, the film for it is pretty cheap as well, and it gives me the same consistent results. I tried to get into instant film with the Impossible Project film and the Polaroid SX-70 camera, but I found that it was too expensive and the film was really, really finicky. I love that the Instax 210 develops in just a few minutes and is SUPER fun to use.
I also have the Instax Mini, but I don't really use that one anymore. Sure, it's smaller, but that's about it. The bigger Instax 210 lets you have a bit more control over the image. For example, you can change its focusing distance, set the image to be lighter or darker, and force a flash. Also, you can't beat having a bigger photo!
Here's an example of when I used all the options to have more control over the image. I set the distance to 0.9-3m, set it to "lighter" exposure since automatic cameras with fixed tiny apertures tend to underexpose, and forced a flash to bring some light back to Peanut's face since he was backlit. Peanut was moving quite fast towards the camera, so unfortunately he moved right out of focus, but I still like how this came out.
Seriously loving this camera. It works best in bright sunny light and you often have to compensate the exposure by setting the option to "L" for "lighter." After a day of exploring the fields of northern California or going to the San Francisco, I love having a nice stack of little prints to pin up to my wall in my room. I just sometimes forget to digitize it as well!