I loved the Ahriman Books, there is also a great Audiobook for them on Audible. Otherwise the Ciaphas Cain Books are great, even though they get a bit repetitive after a while. If you want some Space Marine Action I can recommend the Uriel Ventris Books, even though they sometimes use a bit too much "For Courage and honour!" Also the Infinite and the Divine is just fun

The binding of isaac complete pack is at 38€ at the moment, pretty expensive but worth it, i've spent around 2000 hours with the game

Also Brotato is a nice little game and its like 4 bucks at the moment