Wowhead

I changed from thottbot to wowhead as my main quest guide a few years ago because I thought it had better comments and advice and I liked the interface better. However, over the last year I have found the quest comments frustrating. I use them mainly for information on where the quest is located and any tips on doing the quest. I now often have a hard time finding that kind of information. The comments are mostly on what movie a line in the quest came from or what was meant by that line.
Despite not appreciating all the side-bar comments, I am glad for wowhead and it is still my number one source for quest data.

The ads can be obnoxious, but the information they have is excellent and the search feature is very intelligent.

This site has all the information and help you could need for WoW. Raid boss guides, event guides, quest help, not to mention the location of almost everything in the game, from NPCs, to monsters, to gear, to drops and even includes drop rates. I've saved this site among my search engines so that I can quickly check things while playing WoW and it hasn't let me down yet.

The best information is in the Comments, where people will almost always have posted some type of guide or information, and important posts are made green for easier finding.

I love this website! It's so informative and it helps me

I'm a thotbott --> wowhead convert and it's simpler. If you type in half the phrase you know because you don't remember the rest, it lists the item/quest in a drop down menu for you to choose from!: D

It also updates fast and it says what patch the comment was said in so you can tell if it's outdated or not! Neat!

So slow, that even after I paid for no ads, it almost always times out BEFORE I CAN LOG ON! Come on guys! I can't even leave feedback because I have to logon to leave feedback. Tragic.