I'd say it doesn't IF you are both a completist and want to play the game once.

I however perfer to play the first playthrough of a game "Clean" then check out Faqs and game guides after having beaten it once on a second 100% playthrough.

No, it doesn't ruin the experience but you learn more and earn more experience fighting when you're lost and you'll need all the LP you can get on that game. Also, that game is generally very good on telling you where to go and what to do on there. just buy the guide and only use it if you are lost for more than a few minutes.

I'd only use any kind of guide or walkthrough if I was really stuck and had tried solving it myself but couldn't.

Guides and walkthroughs are stilll not as annoying as the games that used to have a cheat code allowing you to unlock any level and any weapon without having to do anything.
When did the including of cheats in games die out?

I had a friend who used to use a cheat code as soon as he bought the game to say he's got to the last level.
Poor guy, these days he must be permenantly stuck on level 1 of any new game he buys!

W29... It sounds like you are a lot like me in gaming... I prefer a more linear experience as I don't like wandering around and having to figure out what to do next.  I'll lose interest in a game very quickly.  Maybe I have ADD or something, lol, but when reviewers knock a game for being a little too linear, I'm thrilled...  In that sense, I use the guides on games where objectives aren't clear.  I continue to play and try to figure things out on my own but as soon as I feel frustrated, I break out the guide to get the game back on track.

Yeah, kn we are similar, cause I can get really pissed off or lose interest in a game quickly if I don't where to go. Its not ADD or it might be. I can play Halo 3 like crazy, but something like Final Fantasy XII or Xenosaga its really annoying. I tried it with Kingdom of Paradise for the PSP and its kinda hard but I'm lost on a few spots. So I went to Gamefaqs.com to get a walkthrough to help me out.

A lot of games can have these problems where they don't tell you where you should be going next.  Sometimes they do tell you but it's only in one conversation box at one certain time which can make it easy to overlook or easy to forget if you put the game down for a few days.  All of a sudden you pick it up and are like "Where was I going?"  You get bored or frustrated and put it back down.  Well now the next time you pick it up you'll have even less of an idea of where to go.

FAQs/Walkthroughs are good in these situations.  You can easily just glance through and say "Yeah I remember that.  Seems that's where I was going..."

I know I sometimes turn to a guide if I pick up an RPG or the like from where I left after playing other games for a while.  Of course, other times I just restart the game.  I've done that with a few too.  Still, it's another use for walkthroughs that doesn't necessarily involve spoiling the game.

I couldn't do most of any of the Zelda games without one. So in effect, the hint book helps you experience the game even more. In some cases anyway.

No, I like them, but I'm going to use a strategy guide from now on.