Hello George, and welcome to the forum.
Karin Slaughter's Grant County (starting with 'Blindsighted') or Will Trent (starting with 'Triptych') series are grippingly good.
Val McDermid is a brilliant writer who has written a range of stand alones, and series books.
Sebastian Fitzek's 'Therapy' was a book that completely blew me away earlier this year, and I can thoroughly recommend it.
On the forum we have a '20 Books Everyone Should Read' thread, where members have listed their top 5 recommendations, and would be worth a look into. Aside from that I would just take a stroll around the forum, and see what other are raving about.