aseprite for me is the absolute best, its easy (once you get the used to it), theres lots of features and tools to use, its just great overall,
also its manditory we get to see your work lol, btw nice profile pic!
I honestly haven't done any original work in aseprite, mostly I use it to edit pre-made graphics -- stretch, resize, distort, etc. In a lot of games it's essential to have images with a partially transparent background and I don't think MS paint supports that.
The guy on itch.io that first recommended Aseprite to me is using it on his games. I've been pretty impressed with his animations.