If you want amazing, easy to take photos in a small not-tweakable package that won't freak people out if you whip it out at the playground, get the latest Fuji X-100. It seriously violates your interchangeable lens request but it's really really easy to use.
Now that we've gotten easy to use out the way, you want a family of lenses. That means you have Canon, Nikon, and "weird stuff." I'm not doubting that you can get an amazing Sony or Pentax or Fuji or whatever but you'll have to hunt for your family of lenses and "trust" (pray) that they're really what you want.
Canon lenses are crazy compatible. In 1987 or so, Canon said screw this and introduced EOS. Any lens newer than 1987 will work on any camera newer than 1987: no autofocus or aperture caveats. If you're getting a very high-end Nikon FX camera with a built-in autofocus motor, you can use much older Nikon lenses and they'll work beautifully! However, a cheap Nikon can't use older lenses quite like a cheap Canon.
Canon has better bread and butter lenses for cheaper newer. Their 24 mm and 50 mm prime lenses are both excellent and $150 or less. If you get an APS-C camera (you probably are), they have a cheap and amazing wide zoom (the 10-18mm) for around $300! As much as I love Nikon, their cheapest wide zoom is over $800 new. If you're assembling a lens system from scratch and aren't a pro, you can't do it without compromising or breaking the bank on Nikon, but you can with Canon.
Nikon has cheaper camera buy-in. Refurb D3300 and D5300 cameras are available with the 18-55 VR II lens (cheap but excellent) for around $300-500 all the time. I really enjoy my refurb D3100 from Adorama and regularly take great pictures with it. Because of its low cost, I don't worry about using it, say, from the back of a snowmobile (yes, we wiped out a few times).
In terms of the best of the best, Nikon has the best super-pro lenses while Canon has the best super-pro camera. You probably don't want to spend Miata money on either.
Based on your dislike of Nikon, I'd grab a Canon Rebel SL1 and snag a 50 mm f/1.8, a 10-18 mm, and whatever telephoto you can afford (and only if you like fast moving birds or cars). If you're serious about lots of on-the-fly adjustments (ISO, white balance, etc., you know if you are), get a 70D instead.
One final observation, check Craigslist. Don't buy your camera there, but see if there's more Canon or Nikon lenses for sale locally. Craigslist is my favorite place to get a new lens to try out. In my area, the Nikon market is stagnant and expensive while Canon lenses move and are cheaper.