From what I've seen around here, Ren'py tends to be the choice that most users opt for. No matter how good the game is, if it's not in Ren'py then a lot of people don't care.
In my opinion, if you're gonna take a shot at making a VN, you might as well use the engine that appeals to many. Even if you don't know Python, it's relatively easy to get used to if you know another programming language.
As for the 3D Renders/Images, these are the most popular options:
- Daz 3D
Most advanced and professional one. It is the most realistic looking. The only downside is that it doesn't render in real time, so you're gonna have to wait a bit to render each image depending on your PC components. This can significantly slow down game development, but a lot of people really enjoy how it looks and I believe it has the highest potential.
- Honey Select 1
It's pretty outdated at this point, but with a lot of work (and mods) you can make it look good. Except for the main character. Usually males in HS1 look like crap. You'll need to install mods manually for HS1 so that might be annoying and time-consuming. There are many people who enjoy this visual style and a lot of games using HS1 have mediocre renders despite the engine's potential, but Honey Select 2 is already out so it's only a matter of time until HS1 becomes obsolete.
- Honey Select 2
It's the newest version of HS. HS1 mods aren't compatible, but a great deal of them have already been ported at this point. I think it's reached a point where you can safely develop a game using HS2, and there is a patcher to install/update mods automatically. The male model also looks pretty good.
- Koikatsu
If you want anime-looking renders, this is one of the best options. The lighting is terrible and a huge pain in the ass, but if you put in some effort and use some tricks then things can end up looking pretty good. This one also has a patcher just like HS2 for mods. Some people hate Koikatsu, some people love it.
Of course, this is all assuming you want to make a VN (choice-based or not) style game. This is also my personal recommendation. You can also make a sandbox game using the same tools but this requires a bit more work (people hate repeating the same action 20 times to unlock the next quest).
Also, keep in mind that if you want to post your game to Steam, Daz 3D is the way to go.
The other 3 are made by Illusion and are technically under copyright, but Illusion doesn't care about it and they don't take action against devs using them. Still, I wouldn't publish to Steam using them.
The way I see it, you're free to do whatever you want and use whatever you want. But if you're gonna put in a lot of work, why not do it in a way that attracts more people?
Anyways, I'm relatively new to this as well so take everything with a grain of salt. I might've missed something or made a mistake somewhere. If someone else has anything to add/correct, please feel free to do so.
PS: I also recommend playing a few popular games if you haven't already. Gives you an idea of what people want and how things are usually done.
