They're all pretty disappointing.
3dcg does have animations, but they aren't too varied and get old pretty fast. It's mostly used for character building and posing. There's a huge amount of mods out for it, which is great for customizability and accommodating niche fetishes, but sorting through them all is a huge pain. You can also customize character proportions and even animate using external tools, but it takes forever.
Many users use it just for character creation with the intent of importing stuff to MMD and animating there.
Most illusion games aren't very good. Some of the more positively received games include ag3, @home mate, artificial academy and schoolmate 1.
Other games are good for a few faps but get old extremely fast. I'd also advise you to skip those realistic looking games, like real kanojo. They're not very good.
Custom maid 3d is kinda like 3dcg but with a lot less mods and tools and such.