Since probably a bunch of people are going to say Dresden Files already, instead I'll say The Twenty Palaces books by Harry Connolly. These are some of my all-time favorites, and they are criminally under-appreciated. An ex-con gets drafted into being a footsoldier for a massively ruthless secret society of magic-users with the self-assigned duty of policing the use of magic (for which you can generally read "killing anyone who uses magic who isn't them") and protecting the world from the monsters magic can be used to summon. The magic and monsters are both very unique and a bit weird, and I loved the shift in perspective from the typical urban fantasy perspective of relative power and knowledge to the perspective of a guy with relatively little power and knowledge who has to figure out how to beat enemies with a lot more of both. The protagonist is also basically a good guy, and his struggle to reconcile that with working for such a ruthless society is also interesting. Oh, and the author specifically set it as a goal that his setting would have zero vampires in it, because he was sick of those too.

So that's my main recommendation, but just to throw a few others out there: Miriam Black series by Chuck Wendig - snarky foulmouthed girl with shitty death-predicting magic power gets in really bad trouble. Eric Carter series by Stephen Blackmoore - pitch-black supernatural LA noir focusing on a necromancer-for-hire rather than a PI. October Daye series by Seanan McGuire - half-fey PI is trying to rebuild her life after being subjected to a very nasty curse that cost her years of her life, and gets dragged into investigating dangerous things that a sensible person should probably steer clear of.

There's some others, but that should be plenty to hold anyone for a while haha.