What made Blighttown so interesting for me is the sense of despair it instilled. The first time through, I went through The Depths and thought I'd reached the limit of my sanity. It's dark, there are terrible monsters lurking around every corner, and you're bound to get cursed. After finally defeating the Gaping Dragon, I opened the gate only to see that the tunnel went further down... and it was nothing but darkness. Going further down to see this depressing, decrepit underground city built on top of this poisonous swamp was just debilitating. At the time I didn't know about the back entrance, so I thought if I wanted to leave, I would've had to go all the way back through the maze of The Depths.

Many hours later, finally beating the boss and getting out of Blighttown and going back to Firelink to see the fucking sun again for the first time in a dozen hours gave me the most surreal sense of accomplishment I've ever had in a game.