Now that we've experienced " Black Adam" in his own solo thing.. , and John Constantine has a new series coming (HBo) it's time to introduce and emerge out More DC comic pleasant surprises to the cinema and streaming world.
here are my choices live action films and solo DC universe streaming series:
ETRIGAN THE DEMON
AMAZO ANDROID
JON- MARTIAL MANHUNTER
DEADMAN
DARKSEID
GREEN LANTERN CORPS
SOLOMON GRUNDY
RAVEN
ZATANNA
CLAY FACE
WONDER TWINS
PARASITE
MR. MXYZPTLYK
SILVER BANSHEE
BRAINIAC
KARATE KID
DOOMSDAY
SINESTRO
TWO FACE
I can definitely see live action production possibilities for Etrigan, J'onn J'onzz,
Deadman 
, Zatanna and Two-Face. A Green Lantern Corps will likely re-surface in the future since Earth's lantern superheroes are intregal to DC.
I would LOVE seeing Raven getting the Constantine type treatment outside of HBO's
Titans series but it is real iffy. The studio seems extremely content making an increasingly idiotic mockery of the character in cartoons over the years.
I disagree with most of the others because I think their backstories are more suited as supporting role characters than lead characters.
Amazo: Professor Ivo's creation served as major foe of the Justice League members. He did later evolve into a superior cosmic being, which is the picture example you posted. There is a story there but not sure it is powerful enough to convince the studio to support a solo project. It would be kinda like seeing a Dr. Manhatten series or movie appear and that has never happened.
Darkseid: You cannot have the Apokolips rule going solo primarily and not have other New Gods material and characters weighing in heavily. For me, I can see a series with the entire DC Universe omitted except for the New Gods environ for storylines and Darkseid being a major cog in that machine though.
Solomon Grundy: Basically, Grundy is DC's version of The Incredible Hulk. Problem is, Warner Bros and DC have never given his character strong sustaining spotlights in many past projects in animation. Not sure why they would think differently for live action in the future. Who knows though? James Gunn does have the quirky imagination for possibly entertaining the idea.
Clayface: Waaaay too complicated for live action. Don't see that ever happening.
Wonder Twins: Remember. The new Warner Bros Discovery CEO squashed that previously approved project
(thank goodness)
Parasite:
See Solomon Grundy above.
Mr. Mxyzptlyk:
Stop... reaching... for... ban... hammer... STOP!...
Silver Banshee: Dude.
Brainiac: I would like reading your ideas for the character as a major lead character. I have seen him done in SyFy series
Krypton and various animated movies and cartoons but he is highly dependent on other story strings like Darkseid.
Karate Kid: The character is a blast from the past. I had even forgotten him. Do not see him ever getting the Shang-Chi treatment though.
Doomsday:
Superman vs. Doomsday? Better than
Batman v. Superman? I'm certainly game

Past animation matchups were well done. The previous live action matchup in the
Smallville series was both exceptionally brief and sucked. However. The proposal of seeing the character in any other imaginable live action production? Why? For what reason? He was created to kill Superman. That's it. What other material can be written and produced for Doomsday?
Sinestro: They tried it already with the character in a supporting role. I doubt they will do more than that in the future, although he should re-appear in that capacity at some point.