I have thirteen books tagged with
"my top reads of 2021" at The Storygraph, and I don't think there will be any additions to that list in the next 3 weeks or so. Of those 13 the standouts were, in no particular order:
Pathfinders: The Golden Age of Arabic Science - Jim Al-Khalili - a refreshing read in an ever more Islamophobic world.
Gallows Court - Martin Edwards. A very enjoyable Golden Age style mystery with a complex (anti)heroine
The Cuckoo's Egg - Clifford Stoll. My only 5-star rating of 2021, and one I owe to Mobileread forums, since I learned of it here. MR for the win!
I'm not sure what I'm looking forward to in 2022, perhaps book 3 in Martin Edwards' Rachel Savernake series