My all time favorites are Boy Hero Ken: Haunted House Investigations and Leane 2.
The best Netorare stories don't have you making choices that cause the NTR to happen directly. You need to make the logical choice that should prevent NTR and that is what inadvertently causes it, and the NTR needs to come as a shock. (That's what Leane 2 did well)
Heroes NTR Adventure is also another one that I loved. Ultimately, I like games that only give you the illusion of choice, and the NTR will happen without me as the player, having to specifically make it happen.
Another big issue a lot of NTR games makers make is making gameplay that is tedious or requires more then one hand. That was my biggest gripe with Nebel. You need to keep the player on the edge with that feeling of suspense. But having to focus on game mechanics will take the player out of that, as they have to focus on playing the game.
You can check my profile for all the games ive rated on this site. I try to be detailed on why I gave games a particular rating.