Here are a few I like.
Doomsday Wonderland - Female MC that is really badass, no romance, lot's of action, endless transmigration into Apocalyptic Worlds with other Posthumans, weak to strong
When a Mage Revolts - Transmigrated MC, slow start, immense pay-off at the end of the first Arc, extremely satisfying to see the Big Bad fail
My House of Horrors - Best Horror Novel on NU probably, System, action and scary settings, everything you could possibly desire, and an overarching Mystery
Praise the Orc - VR-Game Novel, has a very different tone from other novels of the same genre, action, no harem
Gate of Revelation - Retaliation of the NPCs in a modern-day Game World, I'm only around Chapter 100 myself, but I still find it very interesting
Overgeared - Harem unfortunately, but I didn't really mind it, VR-Game, Character Development on the MC's side, the beginning is a bit hard to read for some, because the MC is still pretty scummy at that point, but the story really picks up
Holy Emperor's Grandson is a Necromancer - The MC is practically OP, it's really fun to read, action
Mages are too OP - The female characters are very annoying, I'm going to say this from the start, VR-Game, very interesting Magic System
To Be a Power in the Shadows - Harem again, Isekai, but more emphasis on the Comedy, also my favorite Comedy novel, but maybe not what you are searching for haha
These are the ones I could think of right off the bat, hopefully, there are some for you here!!
