Yes, I keep track. Finished 519 games.
As for the hardest, that's really difficult... but N+. This game really put my stress to its limits.
-Honorable Mentions-
Batman (NES), Ghosts N’ Goblins (PSP), Volgaar the Viking, Dark Souls 1 / 2, Hotline Miami, She Wants Me Dead, Risk of Rain, VVVVV (going 100%), Silver Surfer, Metal Slug(s) and Megaman(s).