Best Nikon Film Camera?

Hello all!

I am thinking of foraying into film photography. I was just wondering if you all had any opinions on what the best nikon film camera was? I really like the look of the older cameras like the FM2 and FA, but I'm not sure if they would be good buys or not. And also where is the best place to buy used gear like this? I would like to be able to get one for $100 or less, but I'm not sure if thats possible or not. The reason i'm saying nikon is because i already have a nikon camera and some lenses, and don't want to buy into two different ecosystems. :)

Thanks for your time!

David Landis Jr.