Any recommendations for a good modern day thriller?
How modern?
Personally, I love the Arkady Renko series by Martin Cruz Smith.
They take his protagonist (a Russian homicide specialist) from the time of the Soviet Union (Gorky Park), through the glasnost years (Polar Star), the collapse of the Soviet Union (Red Square) and the post Soviet era, right up to Putin's Russia.
These latter books include Havanna Bay (set in Cuba), Wolves Eat Dogs (set in Chernobyl), Stalin's Ghost (back in Moscow and elsewhere, an excellent book), Three Stations (the least good, in my view), and Tatiana, (some of which is set in Kaliningrad).