For me personally I got fed up with doing quests at around 74. Stopped playing on my team for a month, and leveled my main using the random dungeon tool. I had so much fun he dinged 80 soon after.

So I haven't done all the quests in WTLK. Currently i'm leveling my team through the random dungeon tool to gear them up and to gain some exp in the instance running. At some point I might go back to doing the quests but atm i'm tired of doing quests.

I did the wrathgate quest chain because I read it was one of the most epic questchains in wow to date.
After doing this quest chain I have to agree.