This is a setup. One group will scream Canon, another Nikon, and a tiny pack will yell Sony. The philosophers among us will say "Whatever camera you have with you." This implies that you should always carry a camera, and just shoot because it might come out OK. And if not, there's Photoshop (or Affinity).
I beg to disagree. I have said many times that I am a photographer of opportunity. That does not mean that I keep a camera with me at all times (other than the ubiquitous cell phone), and snap away. No, it means when I have an opportunity and some desired subject matter (or perhaps location), I will take advantage of it.
Since this generally requires at least a bit of thought, my selection of camera is important. I shoot film and digital, both in small and medium formats, and large format film (4x5 and 5x7, with 8x10 on the way). So if I am going to shoot an event (wedding, festival) I am taking small format digital. It's easy, rugged, and my selection of lenses (either owned or rented) is vast (though I almost always end up with my 135 f2 in the end).
But if I am deliberately planning a portrait shoot, especially if for someone else, there is no better choice than medium format digital. And drag out the flash. It's tougher, more demanding, and the results are miles ahead of 35 mm. I choose a better camera, and I get better results. My skill level does not change.
Finally, if it's for me, it's film. Large format film takes time, patience, and planning (and a strong back). I have to load the dark slides with my selected film, grab a lens or two, make sure the light meter has a good battery (or use my old $15 Weston), be certain the dark cloth is packed, get the big tripod out and assemble it, and lug it all somewhere. Spend 5-20 minutes setting up the shot, press the release cable for 1/30 of a second, and reverse. Come home, spend two hours developing, scanning, and printing (maybe one negative), or send the color film off with $5 per sheet for developing.
And the results, 4 out of 5 times, are worth every minute of it. It's magic. My keeper rate is higher, and the look is unique.
Now, don't have two or more cameras? Then use what you do have. When all you have is a hammer, every problem is a nail. But I'll bet you do have to or more lenses, so don't just leae what's on the camera there; THINK about it.
Do most people care? Can they ever tell? Nope. Do I care? Nope. But that is a blog for a different day. Today my point is the best camera is the one that fits the job.
P.S. - I am an amateur - a mortal among the gods of film. I admire them; I envy their knowledge and skill; and I hope that someday I can consistently make images like theirs. In the mean time, please see Kenneth Lee's new website. It's all large format film, and it shows that mundane objects like pottery can be truly beautiful.