Probably my favorite VNs come from Love Conquers All Games (Christina Love's stuff). The best is probably the Hate series: "Analogue: A Hate Story" and its direct sequel "Hate+", but all her stuff is good. You play a space investigator trying to figure out what happened to a derelict generation colony ship by reading log files and conversing with the still-active onboard AI. It's way better than it sounds.

Another top favorite is "World End Economica". Designed by Isuna Hasekura, better known for "Spice and Wolf", it is a rare example of finance fiction in the VN space (which takes place on the Moon and features Hasekura's wonderful blend of fantasy, finance, and romance).

I second the Steins;Gate series. Taken together, S;G and S;G0 probably tell one of the best stories ever told... though it requires a great deal of time and thought to figure out what's really going on behind the scenes. All of Mages stuff is kind of like that, though I think Steins;Gate is the only one where it's actually worth the effort.

Finally, if you're just looking for some happy goofy adorkable romance, Pixelfaxe's VNs are all good. You may as well start with their first VN, "Ace Academy", which features a bunch of college aged kids at a giant robot fighting academy, but there's also their fantasy isekai "Crystalline", their reverse isekai "Ethereal Enigma", and their upcoming space adventure "Astral Ascension". The art is beautiful, the girls are gorgeous, and the voice acting is the early work of some people who ended up kind of famous (Amalee, Sydsnap, and others). Really fun stuff.