Yeah, Gamestop likes to try and sell game guides whenever they can. Honestly, I feel like game guides are more like collectibles now... because the internet almost always has a wiki for the game you're playing. I've been using UESP for years.
Though, I did look up stuff for Skyrim. Daedric quests (for an achievement, marriage (didn't believe it was in the game at first! haha), houses, and some quests to see if they were buggy. Nothing really crucial though.