Anything that's long, visually dull, and lacking save points (in a game that has them). I remember the Omega Ruins in FFX being quite annoying to start with. Although that decreased when you overpowered the hell out of your party.

Quote Originally Posted by Luis Suarez View Post
A bit of a cliché one but still the Water Temple from Ocarina of Time. My first time playing it I got completely stuck there and didn't go back to the game in about a year.

Whenever I play it again I always remember to pull that damn block out near the start.
It was infinitely nicer on the 3DS remake.