My 2 favorite games on steam are/were early access.

Empyrion Galactic Survival, my most played game on steam (just under 1k hours). I don't even remember how much I bought it for, but something along the lines of $20 or less.

Clunky as all hell, but man whenever I play any other space game, it makes me want to go back to Empyrion. TECHNICALLY not in EA anymore, but they are still adding tons of stuff lol

7 Days to Die. A pretty popular one. I believe this was one of my first games on steam. Tons of hours, also like $20 when purchased.

Valheim has so much potential, I'm excited to see the level it gets to.