These days I just load up the official site's web version [0] but lately they've crammed more and more ads onto the page and Ublock Origin can't keep up. Sometimes the tab totally freezes. Makes it difficult to enjoy.
https://www.firstpersontetris.com/
It's fun to give someone without telling them the whole view rotates whenever you rotate the piece because it's extremely disorienting if you're not used to it, but after a bit of practice it becomes easy
For single player https://jstris.jezevec10.com/ or https://simon.lc/tetr.js/ are the best.
After that it's probably classic Game Boy Tetris.
For modern Tetris, Tetr.io or jstris.
The latest I’m aware of is [0].
I have a keychain toy I got as a child that has a cheap LCD recreation.
<strike>clearly the best option is bastet on linux</strike>
It's actually not that difficult --- it's probably one of the most cloned/ported puzzle games, but almost always called something other than Tetris because their lawyers really don't want you using that name. "Russia Block" is/was a relatively common synonym.
The game mechanics are actually quite complex when you include all of the details. Sure, you might say those details are superfluous, but there’s a reason many people prefer classic Tetris over more recent versions. Nintendo’s original mechanics are much more challenging but also very satisfying to play with.