Good design is familiar.
Bad design is boring.
Great design is exciting.
Good design embraces human nature.
Bad design exploits human nature.
Great design is humane and humanistic.
Good design guides.
Bad design controls.
Great design invites.
Good design drives habit.
Bad design drives frustration.
Great design drives passion.
Good design teaches.
Bad design lectures.
Great design has you teach yourself.
Good design is invisible.
Bad design calls attention to itself.
Great design calls attention to what you can do.
Good design celebrates accomplishments.
Bad design loudly celebrates minor accomplishments.
Great design enables accomplishments.
Good design does what the user wanted.
Bad design does what the designer wanted.
Great design does what the user didn’t know they needed.
Good design is at the user’s skill level.
Bad design never asked the user.
Great design makes everyone think they can use it.
Good design is intentional.
Bad design is planned (exhaustively, on paper).
Great design reveals itself while working in the materials.
Good design gets people to pay for utility.
Bad design gets people to pay as quickly as possible.
Great design makes money as an incidental consequence.
Good design makes companies.
Bad design can make plenty of money.
Great design builds legacies, cultures, and communities.
Good design converses.
Bad design tells.
Great design connects people.
Good design executes on the possible.
Bad design ships on time.
Great design reaches for the implausible.
Good design has only the parts it needs.
Bad design is cluttered.
Great design has fewer parts than seem possible.
Good design doesn’t fail.
Bad design fails a lot.
Great design fails even more.
I have done good design.
I have done plenty of bad design.
I always want to do great design.
Edit: if you are looking for the GDC talk I gave with this title, check here. Basically the same as the above, with a bunch of additional material.