What are some good tools for doing 1990s pixel art? Specifically sprites, but maybe some larger backgrounds. I see someone's done a JS version of DeluxePaint! Any others people really like?

Slightly heretically, I'd love one that handled alpha channels well.

Recs so far:

Aseprite
Pro Motion NG
grafx2
piskel
pyxel edit
Pixelorama
Cosmigo
Libresprite

My brain is very small, so starting with the #1 most common which is Aseprite.

This was an incredibly helpful video on Aseprite for a newb like me:
https://www.youtube.com/watch?v=59Y6OTzNrhk
An Aseprite Crash Course In 30 Minutes

YouTube
@TomF I've caught a couple of Adam's live sessions working on Insignia and it's crazy how much breadth of knowledge he has over the things required to make a full game.