What non cannon stories do you recommend?
Hmmm, Non-Canon on DCU is hard. There’s not a lot that heven’t existed in canon at some point. If you aren’t looking for DCU comics, try Superman: Red Son or Long Halloween. For a DCU one, I guess Wildstorm?
A few suggestions available on DCU:
-Batman: Red Rain
-Justice League of America: The Nail
-Justice League of America: Another Nail
Outside DCU, the Earth One line of original graphic novels are non-canon to the main DCU continuity (yet have their own canon). The Wonder Woman and Superman volumes are quite entertaining.
Oh yeah. Duh Injustice !!! Fantastic read and year one and two are available on DCU!