I would recommend similar VNs that Gobbo and Sanahtlig have.
Steins;Gate: because it is well known among the Anime Community as a popular Anime. It is more accessible to a wider audience from not having 18+ content in it. And is overall a fantastic story. The routes in the game give good examples of showing how the several endings you can get in a VN are not “bad” endings, and how it is simply a different route that Rintaro could’ve taken, not necessarily being more “right” or “wrong” compared to the other choices you can make.
Aselia the Eternal: For most of the reasons Sanahtlig states. It’s nature of being a JRPG/VN hybrid will help fans of JRPGs get used to the structure of VNs and how it still has good gameplay. I’ve really loved the Unique Battle System Aselia has created by having the 4 elements of Red/Green/Blue/Black, each with their own characteristics they apply to characters (both protagonists, alies, and the enemy) And it may be from this unique system that I love it so much. It gives a great turn based strategy element to it which reminds me of how I love Chess. And I love how this system was carried over into Yumina along with Seinarukana as well. Also considering this game and Seinarkana are available on Steam now in an all ages version both games become accessible to a lot more people who wouldn’t have known about the games before as well.
The more mature story themes and overall “serious” feeling of the story of Aselia is also what makes it appealing I feel. You somewhat feel the weight of becoming involved in a War and having to kill people to protect the ones you care about. Which is what the protagonist feels throughout the whole game.
Yumina the Ethereal: I would also recommend for any new VN player. It was pretty much my 1st VN in practice and is what got me aware of JASTUSA and their involvement in legitimately bringing the VNs I really wanted to play to countries outside of Japan. It has a lot of great comedy I felt, and the lighthearted nature of the game with the Student Council President Election and the interesting battle system based off of Aselia’s is what made the game for me. The 4 main characters you eventually got to know and love each of them for their own characteristics. And you get to spend the whole game with Ayumu, Yumina, Kirara, and Ai. Most of the sex scenes in the game are optional for people who are not a fan of them and are more interested in the other elements of the game. And I can’t get enough of the battle system. It’s so good I feel.
For the VNs I’m playing now. I’m still in the process of playing Seinarukana. I’ve loved the game and have been wanting to focus on it. But I’ve gotten busy because of IRL matters related to my job, and haven’t been able to focus as much on playing VNs or games overall that I want to. I’m wanting to change that, and I have gotten past the Magic World (With the very difficult Berbalzerd fights there). I will eventually beat the game. When I feel I can dedicate the time to it. I will also buy Flowers, as I’m interested in that VN.