IMDb now has an "adult animation" tag that is worth looking into.

I'd suggest:

• Fritz the Cat (1972)
• Fantastic Planet (1973)
• Heavy Traffic (1973)
• Wizards (1977)
• Son of the White Mare (1981)
• Time Masters (1982)
• Fire and Ice (1983)
• Rock & Rule (1983)
• Starchaser: The Legend of Orin (1985)
• Gandahar (1987)
• The Haunted World of El Superbeasto (2009)
• The Spine of Night (2021)

Series:

• Spicy City (1977)
• Æon Flux (1991)
• The Maxx (1995)
• Love, Death & Robots (2019) - an anthology series so a collection of shorts
• Primal (2019)
• Too many on Adult Swim to make a complete list of but Metalpocalypse and Mr Pickles stand out in this context

Some Japanese animation that may fit the bill:

• Dallos (1983) - A scifi/political OVA from the creator of Ghost in the Shell.
• Kite (1998) - Action/revenge movie. Includes porn scenes, but IMO this is not a typical "hentai" movie.
• Ninja Scroll (1993) - Action movie set in pre-Meiji era.
• Megazone 23 (1985 to 1989) - Series of scifi/cyberpunk movies. The concept and especially the first movie likely served as an inspiration for the Matrix series.
• Perfect Blue (1998) - An exploitation/thriller that IMO easily beats most Hollywood fare. Was originally supposed to a live-action movie, but they switched to animation because they couldn't get the budget for a live-action movie.
• Vampire Hunter D (1985) - Solid vampire themed action movie.
• Wicked City (1987) - Action/horror with gothic themes and nudity.