A) I don't hate mainstream stuff, I hate the fact that mainstream works are the only ones that get any sensible recognition, with people not willing to explore more around, either out of fear of wasting time or lack of interest. All of this is fair, but it is my personal grievance.
B) I barely read any translated VNs, simply because my interest lies elsewhere (which led me to discovering some genuinely amazing things). And the things that I did read is the mainstream stuff that everyone else did at this point. For this reason I am not quite qualified to recommend many translated works since I do not know of their quality.
It also vastly depends on what kind of work you are looking for, length and genre wise. I simply can't know what you will or will not like and since they are a massive time investment to begin with, even the shortest.

That being said, if you like comedy oriented works with light drama and profound messages about found family and friendship bonds, HARUKAZE/TokyoToon works, such as "Marco and the galaxy dragon" and "Noratoto" are a great choice.
After reading "everlasting flowers" by sprite I can firmly recommend it as a work that tackles topics of social anxiety, feelings of isolation and hedgehog dilemma.
If you fine with need to deal with technical limitations and issues, picking up fan translation for Amagami is not a bad idea if you want to have some experience with critically acclaimed dating simulator.
Works by former minori like "ef - a fairy tale of two" and "eden*" are great examples in bittersweet drama field, which showcase the beauty of ever so fragile life.
More on the topic of beautiful fragile life - one of my most favourites is "Tomoyo After - it's a wonderful life". Really underappreciated work of visual arts, which I believe deserves more recognition. Maybe a little bit too honest in what it tries to convey, but there is a sincere positivity behind the gloom in it.
I am currently still in the middle of reading it, but "Usonatsu" by lycoris is an interesting romance story with premise built on conflicting emotions and feelings of 'love'.
ISLAND - is a mix of a mystery VN about defying own destiny combined with soft science fiction as a secondary element, good work in case if you like to theorise and rattle your brain a little.
As much as I don't like SciAdv as a collective work, each individual entry is a good entertainment piece in their own right. Chaos series being more on the melancholic side, while rest on more cheerful facet. Decent reads maybe outside of always shittily made flag systems for routes.
While I have not read "Amanatsu" yet, I am confident in quality of AzarashiSoft games which they established with their approach to creating pure love stories with emotional touch which leaves you invested in its soothing and calming sweet embrace.
Recently there was an official (re?)release of doujin "Nagi no Koi", which looks pretty interesting, have not tried it yet, but I think showing some help and recognition to small creators is a nice thing to try and do, so yeah.
As much as I would want to recommend "KimiNozo" this "enhanced edition" is a scam not worth money they asking for it, starting with outrageous crowdfunding campaign to the end product price for the kind of quality it is. Which is a shame, but at this point I would recommend you to watch anime instead, ot conveys idea well enough, even if some anime original liberties.
Grisaia is good enough as a action spy flic, which kind of fumbles the bag by its final entry. No clue about phantom trigger outside of that it is the same spy action flic.
I read "Flowers" by innogrey for about an hour and can testify for its atmosphere at the very least. It got that feeling if you know what I mean.
That's pretty much it for now, at least from the top of my head, so here you have it.
Some of my friends are avid qurippo fans so nukitashi is a good choice I can trust them on, being a more or less social commentary on modern world combined uniquely with adult sense of humour and topics.
Will repeat myself a little and say that I don't particularly hate any "mainstream" eroge, I just really wish people would explore more, because there are definitely hidden gems just for you about which you don't know.
I do voice my dislike of publisher practices though, that much is true.
Also, go try out 428 - shibuya scramble, it's insanely funny and good.