I tend to buy old Soviet stuff like Zenit, Lomo, and some others. My Zenit ET is my personal favorite. They are made like tanks and have always been super reliable for me with great image quality as the lenses the Soviets made are mostly very good to excellent optics. I also have some DDR Zeiss Pentacon and Polish PZO stuff. Fed are also not bad, probably only decent rangefinder type which are essentially an excellent copy of earlier Leica model. If you go that route, I strongly suggest to get bodies with the M42/Pentax K mount for ease of lens interchangeability.
Of course there is more 'regular' stuff like Nikon, Canon, Pentax. I would just look for good deals on ebay and the like, then look it up on the model and confirm it's not a piece of ****.
You could also consider some medium format 120mm. Some of them are pretty good deals like Mamiya, Pentacon, Bronica, Kiev88... Medium format is very interesting, but the film is generally more expensive and it's getting tougher to find places that will develop it that don't require sending it away.