Looking through Steam sales for sub-$10 titles with "Very Positive" or "Overwhelmingly Positive" reviews is a good filter.

Some of my favorites over the years include Slay the Spire, Celeste, Vampire Survivors, and FTL.

Edit: How can I forget the "holy trinity" of mystery indie games? Return of the Obra Dinn, Outer Wilds, and Her Story. These are brilliant games that really make you feel like a detective.

Honestly, steam. I look at steam queue occasionally, I also look at "similar to this" section on a game I played (store page). I search for tags of things I like, I also use the steam experiments (although most of them are integrated) and I make a point of looking at all games on discounts when there are "festivals" in the dedicated festival page. Then world of mouth.

I also make a point of grabbing stuff only when positive rating is 90% or more (recent) and of things that have at least ~5000 reviews or more. There are exceptions obviously, but this helps a lot to trim down the things I don't love, my backlog is already infinite.

I can give you a list of my favorites if you want and you can trim down. As I said, world of mouth!

Sibling answers are good but if you want to go deep, twitter/game dev mastodon is a great place. I try to follow anything that looks or sounds interesting, though it often takes years before actual release.

I've found many good ones just from looking at games with high review score on MetaCritic. This is how I found Hollow Knight and Chained Echoes, for example.

On a side note, it's quite astounding what just a handful of people, sometimes a single individual, can accomplish. It becomes quite clear that the main limiting factor when trying to create a good game is simply your own imagination and creativity. A large team with a huge budget seems to be just as much of a curse as it is a blessing.

Steam 250 [0] lists the top-rated games. You can filter by tags, price, date; but the most interesting category for me is the "hidden gems".

[0] https://steam250.com/

Cannot recommend Adam Millard's youtube channel enough. Every year he reviews his top games, many of them make it to my wishlist. ex. https://www.youtube.com/watch?v=c0Eo7fwGBJ4 You can have a look at other years as well.

My personal method is to find a Youtuber who you enjoy watching that has similar taste to you and plays a variety of games. Also gives you a preview to decide whether you like a particular game or not.

Here and there usually, browsing steam by rating works decently.

I'll throw out a recommendation for Dave The Diver, fun little oddball game.