While I'm not quite sure where horror ends and weird begins, my suggestions would be these.
Jungle: my favorites are Fiction House titles. Fox jungle comics also have plenty of Iger shop good girl art. Overall, I consider jungle titles to be a somewhat racist genre, often mostly an excuse for white women in bikinis ruling the natives, ala Rider Haggard's She.
Horror and Weird: I'd rate Harvey titles pretty high in this area. Do an artist search at GCD (Comics.org) for Rudy Palais and check out stories by him. If you like weird, some of his art is truly that.
Science Fiction: the very best were in EC Comics, which aren't public domain and aren't found here. For space opera with good girl art, Planet Comics from Fiction House are quite good. I also have a fondness for some of the ACG sci-fi titles which overlap into 'weird'.
Western: my pick for a sleeper series is Dell's Gene Autry's Champion with some very charming and lively art by Mo Gollub in many issues (not all).
Crime: I'd probably dive into the Lev Gleason crime comics (most famously Crime Does Not Pay) which had some strong art and quite literate stories. Hillman's Real Clue Crime also has some decent art and stories (some garnering Doc Wertham's wrath, if I'm not mistaken).
For overall insanity and wackiness, I'd check out Columbia's Sparky Watts series by Boody Rogers, also their Big Shot Comics, which was a variety comic with some good art by Ogden Whitney, Boody Rogers, and Fred Guardineer among all the newspaper strip reprints.
For across-the-board quality, I'd check out Quality comics. One of my personal quirky favorites is The Barker, which are really fine stories (with humor and crime elements) by Klaus Nordling, one of the all-time greats. Nordling also did Lady Luck, one of the best (and cutest) super-heroines. Quality's Blackhawk comics, with a lot of art by Reed Crandall and Chuck Cuidera, is always solid, and their T-Man series is primo Cold War espionage and action, occasionally over the top. Needless to say, Quality's Plastic Man and Police Comics (which had Plastic Man stories as well) are highly entertaining and usually feature good Jack Cole or Cole-influienced art.
Finally, I'd check out various St. John titles. They always had top quality stories and art. Their Tor title had some terrific Joe Kubert art.
This is all subjective, I admit, but that's my two cent's worth.
