Great thread.
For an interesting series of books I would recommend in order:
Hitler's War on Russia by Carell. This is the deluxe version.
The Unknown Black Book - The Holocaust in the German-Occupied Soviet Territories. Tracing the ride of the Einsatzgruppen broadly across all German Army Group areas.
Masters of Death - The SS-Einsatzgruppen and the Invention of the Holocaust . "Invention" here, meaning genesis of the Holocaust. This is a no-holds barred narrative of the German rear echelons in the wake of Barbarossa.
Barbarossa Derailed v1 Glantz's latest book just released last week. Vol 2 is due in a couple of months time. Should be an indepth contrast to Carell.
Scorched Earth. Volume 2 of Carell's East Front magnum opus.
Decision in the Ukraine by Nipes. Takes the action from Kursk through to the pursuit against the German South.
The Korsun Pocket by Zetterling (of the Germans in Normandy fame). Where once there was a dearth of literature, many studies are now blossoming.
Soviet Blitzkrieg The Battle for White Russia 1944. Dunn's classic expose of Bagration (I bought this in hard cover years ago for $100 - what a dope!).
Then any number of books that cover the campaigns through Hungary, Poland and Germany. I particularly am interested in Glantz's treatment of Leningrad and the end of Army Group North in
The Battle for Leningrad 1941-1944 .
I personally feel that any study of the East Front without an examination of the tragedy, logistics and economics of the Holocaust is meaningless. In this light, both Carell and the writings of the the Soviet-side specialists such as Glantz and Erickson become of equal value. Two sides to a war in which the goals of the protagonists were far from clear.
PS: I forgot to insert after Barbarossa Derailed the classic text on Stalingrad -
Enemy at the Gates (1973). Not the book of the movie but the classic by William Craig that inspired of all things, the board game "Squad Leader" in its operational grit.