I suggest any 18+ VNs to have a NSFW tag put on them if people are recommending them, to distinguish them, some also have All Ages versions so people can check them out without 18+ material.
The entire Ace Attorney series is considered a Visual Novel, btw, including the Miles Edgeworth spin-offs.
On my hand I'm re-playing Osananajimi Wa Daitouryou (NSWF) and Kamidori Alchemist Meister (NSFW) and I'm really waiting on the release of the Perfect Edition of Little Busters, which is the 12+ edition which includes all the routes from EX.
My list of waiting on translations would take forever that I'd spend all of today listing them otherwise, Little Busters and Angel Beats 1st Beat are just biggies on my list.