It's a tossup between Dark Souls 1 and They Bleed Pixels for me. The first I ragequit and have never touched since... the second I just hung my head in defeated shame and gave up. It's so brutal :(
I did the exact same thing with Dark Souls. I'd seen a thousand different people declare it was their favorite game of all time and decided to pick it up on sale once. I tried it out for a little over an hour and realized I hated it.
For me, it's because of how buggy it is. It's one thing to not be good enough, it's another to somehow bounce off the top of an enemy and glide into a canyon and instant die