I'm into the adventure and Role Playing Genre, and I don't like to read. Adventure and RPG games tend to focus a lot more on story, so for me, video games replace books to find my stories.
With that, when I get stuck in a game, I'm stuck in the story, and sure it'd feel better to figure it out myself, but that's what replay throughs are for. I do use guides, but not very often. Rarely do I need them, but when I do, I only hesitate a little to use them. Obviously the feeling of completion is a good one, but when the story is at stake, I don't want to have to give up completely, so I'll resort to a guide. On replays of the game, though I never use the guide. Mostly for the reason of I don't really need them anymore, but also for the reason that this time I'm going for that sense of completion.
Besides, the sidequests are where I really feel that sense of completion, completing the game 100% for me is the greatest sense of completion. Sidequests rarely need a guide, so I'll never use a guide for those, even on my first play through. Sidequests for me are like finding all the little game's secrets, so it's fun to discover them. Using a guide ruins the discovery aspect of it.