The best camera to shoot is really the one you have on hand, but that doesn't answer your question. I think you're after the machine that just feels most like an extension of ourselves, that we simply like to use
I have two. The Olympus Pen F half-frame, and the Pentax MX. And I'll go in that order. Reason? First of all, there is seldom a reason for an enlargement larger than 5x7 or at most 8x10 unless it's going to be an exhibition print, framed. So 35mm will always do, especially if you're skilled in the darkroom and can make good internegs for giant blowups. Secondly, the vast amount of films available for 35mm. Other formats are much more limited. Thirdly, these cameras are small and light, tough, ergonomic, and have fine optics. It is quite amazing what you can do with Pan F or Adox 25, a tripod, and a Pen FT. The MX speaks for itself, arguably the most underrated pro-level 35 ever made
If I were allowed, I'd add the Pentax 645 medium format. I could live with just this camera (or either of the other two), because it's just simpler to deal with 120 in the darkroom to produce top notch results. The Pentax 645 is ergonomic and produces exquisite images. Small and light, and intuitive.