I love my 8Bitdo Ultimate controller. It’s comfortable to use and holds a decent charge. Having a charging stand is really useful too. If you have multiple non-PC devices, I would recommend getting the Pro version so that you can use Bluetooth. Otherwise, the USB one will work well.
Only other minor negative is that the d-pad is a little mushy so I will occasionally hit the wrong direction accidentally. So not the greatest for fighting games.
If you don’t need the charging stand, there are cheaper USB only controllers too.
Lastly, if you want to try to improve your posture, my family bought some chair restraint straps for my grandma who kept tilting in her chair. The ones I linked aren’t what we got her but they were the cheapest I could find. You may also want to get your eyes checked. Could be the reason you’re leaning forwards so much is because you can’t see as clearly as you think.
Protagonist has got to be Bayonetta (though it’s based only on the first game). Her character growth in the first game was so good, even if the plot was a little convoluted. Never finished the second one since I didn’t like playing on the Switch and never played the third one. Hope her character is still good though.
Honorable mentions are Kassandra from Assassin’s Creed Odyssey, Elizabeth from Bioshock Infinite, and Stelle from Honkai Star Rail (though this one is mostly for the absolutely ridiculous dialogue options we get to choose).
Favorite female antagonist is hands down GLaDOS. Such a fun, sarcastic, and likeable villain.
Here’s a full list of crossplay Xbox and PC games. I figure if it’s on the pc, there’s a good chance it could be played on the steam deck as well.
Notable mentions in there that I’ve played and enjoyed are Destiny 2, Overwatch 2, Remnant 2, Left4Dead 2, (I’m seeing a pattern here), and Deep Rock Galactic.
Thimbleweed Park seems to fit your criteria. One of the reviews even compares it to Twin Peaks. It’s a point and click murder mystery adventure game with where you have to switch between 5 characters.
It’s been years since I’ve played but I think the setting was in a fake Northwest Pacific town.
Fun fact, the names in the phone book and the titles/stories of the books in the library came from Kickstarter backers. Some of the books were pretty funny.