Holga

I got my first Holga more than 20 years ago.  It was a trip -- I think it was about $20 and the instructions that came with it said that the first thing one should do is throw away the lens cap.  Everything is plastic and the back leaks like a sieve and doesn't stay on very well, so I took to taping the back on with electrical tape.

But the Holga (like the Diana that came way before it) takes 120 film which creates big beautiful negatives.  Additionally the Holga is incredibly unpredictable, you never know what you'll end up getting.  So that same excitement one gets when getting film back from the processor is tripled with the Holga.  I have many more expensive cameras, but I can honestly say that some of the pictures I'm most proud of were shot with the Holga.  Pick one up.