Depends, do you mean the ones that are on Steam or others too?

Also it depends of what you are interested in, in my case those are ones that I consider the best out there (those ones are in no particular order):

Summertime Saga Love & Sex Second Base Another Chance Paradise Lust A Town Uncovered Four Elements Trainer Witch Hunter Insexual Awakening SexNote Imouto! Life ~Fantasy~ Quickie: A Love Hotel Story LonaRPG Teaching Feeling Breeding Farm Out of touch

But in my case I like those for stats management and stuff like that.

For story what I would recommend is (those are in order from best to last): Out of Touch! Love & Sex Second Base Summertime Saga Paradise Lust

For RPG puzzle and 3D as well as a very good story I recommend: Lust Epidemic Treasures of Nadia The Genesis Order In exactly the order I said them as they are part of the same story!