What does @Mark_Kriegsman and @Daniel_Garcia think about this?
They both have their wishlist. 
We’ve discussed this a whole bunch (of course), and there are multiple ‘correct answers’. Sometimes you want a super cheap thing. Sometimes super small. Sometimes you want every possible pin broken out. And power management is always an issue.
My favorite riddle ever is: what do you sit on, sleep on, and brush your teeth with? And the answer is, of course, “a chair, a bed, and a toothbrush.”
We always seem to complain about memory, and processor speed. Is there such a thing as a Due on a stick?
You want a Teensy 3. They’re great.
Specifically the 3.1 
I use so many different controllers on different projects, it’d be really difficult for me to describe an “ideal controller”
Same here. Sometimes something as simple as a Tiny85 will do, other times a 328p will do, and yet on other occasions I want a 32U4 … Or move completely to a faster ARM based processor.
That said, there’s nothing that says we can’t create our own series of controllers …
You gotta get Mark and Daniel paid somehow for creating this great library! FastLEDuino!
Surely you mean we do … Honestly though, we could create a few different controllers, for different situations. For example, use a Tiny85 when you’re going to drive a single string of less than 100 pixels. Use a 32U4 for USB capabilities (and we could make it into a stick, or needing a cable) … stuff like that.