Some of my favorite reads for each of your characters/properties of interest:
-Aquaman: issues 15-39 of his 2003-2006 ongoing series. Underrated runs by Will Pfeiffer and John Arcudi (with a sprinkle from writers John Ostrander and Marc Guggenheim along the way).
Patrick Gleason (Green Lantern Corps, New 52 Batman and Robin, the Rebirth volume of Superman, etc) provides the majority of art in these issues and it is good.
-Black Adam: his six issue, self-titled mini-series from 2007-2008. Written by Peter Tomasi and drawn by Doug Mahnke.
-Darkseid: Superman/Batman #'s 8-13, the Return of the Supergirl from Krypton arc. Great, great stuff. Darkseid is a bastard and this arc perfectly exemplifies that.
-Doctor Fate: he’s been a focal point in recent issues of Justice League Dark (not on DCU), but for a solo gig, I liked his 2015-2016 ongoing series.
Written by the legendary Paul Levitz, it offered an interesting look at the character with handsome art to boot.
-Green Lantern: Geoff Johns’ run is everyone’s go to (and for good reason, it is absolutely wonderful ), but I’ll go with a different choice here and highlight Green Lanterns (2016-2018) which stars the Jessica Cruz and Simon Baz GLs.
Outside of DCU, the current GL title, The Green Lantern has been a great read. Hal Jordan stars in it and its a wonderful potpourri of fun, weird, out-there science fiction. Written by Grant Morrison and drawn by Liam Sharp.
-New Gods: Jack “The King” Kirby’s 11 issue run from the very first New Gods series.
The Orion ongoing series that ran from 2000-2002 is fun too. It’s written and drawn by Walt Simonson.
-Poison Ivy: the Poison Ivy: Circle of Life and Death mini-series from 2016. Pam’s first starring book (that I know of offhand).
-Stargirl: Stars and S.T.R.I.P.E. . It was one of Geoff Johns’ first ongoing gigs at DC, and is a very fun series. It’s bright, cheery, funny and action packed.
-Zatanna: Her 2010-2011 ongoing series (her only ongoing) is heaps o’ fun thanks to DCAU scribe Paul Dini’s magical writing.
The Crisis of Conscience arc from JLA (1996-2006) #'s 115-119 prominently features Zee as well. Its written by Geoff Johns and Allan Heinberg. The cover of #118 features Zatanna and is a beaut!
Hope all of that can be of use to you =)