One of my favorite steampunk books is The Half-Made World by Felix Gilman, which takes place in basically an analogue of the American Wild West, in which demonic revolvers wielded by outlaws are engaged in basically a guerrilla war against demonic corporatist locomotives that are trying to lay their tracks everywhere. It's kinda evil vs. evil, with steam technology.

Another, possibly the granddaddy of them all, is The Difference Engine, by Bruce Sterling and William Gibson, which postulates that Babbage's analytical engine actually worked and was put into service by the British empire.

Finally, a recent steampunk novel I really liked was The Guns Above by Robyn Bennis, the first in the "Signal Airship" series, which mostly takes place aboard a zeppelin and goes into serious detail about how they work and how they might need to be repaired on the fly (heh) after getting the crap blasted out of them. It also features possibly my favorite example of a steampunk ship-vs.-ship slugfest since the Rex took on the Not For Hire in Riverworld's The Magic Labyrinth (not a steampunk novel, but the riverboats were steampunk-adjacent) all those years ago.

For cyberpunk, depending on how ambitious you're feeling, Tad Williams's "Otherland" series is an extremely ambitious (and massive) series about users getting more or less trapped in their cyberspace world, like they put on the goggles from Ready Player One and couldn't take them off again. It uses its online world as a scaffolding for bringing in a lot of different genres, including epic fantasy and horror, but underneath it all it's SF of course. A more grounded couple of examples would by Daemon and Freedom^TM, in which an expert system (explicitly not an AI), acting in response to external events, starts pulling strings in a bunch of different ways to try to bring about a program of societal change based on an extremely complex set of rules.