I don't read much for plot, and mysteries tend to be about plot.
Unless they're not.
I have one mystery series I really love. It's a famous mystery series I'm sure you've heard of:
The No. 1 Ladies Detective Agency by Alexander McCall Smith
I haven't read them all, but I've read a bunch, and I can easily slip into Precious Rmatswe's world, a world so different than my own.
But I've found a new series I believe I will dabble in for some time to come. These books are complete in and of themselves. There are no cliffhangers at the end that force you to read the next book. I'll pick them up at my leisure, but this series has a great world and a great main character: Flavia de Luce.
I've only read the first book, but I thoroughly enjoyed it. I don't read novels for adults often, so I'm always surprised by the amount of unnecessary text—the diversions the narrator will occasionally slip into—but it is nice to fall into those little diversions occasionally, as long as the author gets back to the story quickly, and Alan Bradley does.
Check out, The Sweetness at the Bottom of the Pie if you like a good mystery. And even if you don't!