The most fun I have had in WoW, was the esperience of leveling my first character. It may have taken a year, but I enjoyed it. Blizzard put huge amounts of work into the stuff before 60(the original level cap). But now, there seems to be no one going through that. When I was leveling the first time there were still hundreds of people on my server going through it the first time and Molten Core was a long off dungeon that did not mean much to me. And though it was a horrific trial, getting ganked had an element of fun to it, being a druid I would shapeshift out of higher level snares, and dodge and evade my way into an escape... and green whelp armor was hilarious when it procced a full tier 1 rogue.
Quests did seem to have meaning, and hiking across Azeroth was a wonder of exploration and admiration of the game designers.
But now, the leveling has become a thing of alts, and a grind to hit 70. Molten Core is now a thing of the past, made obsolete by TBC, along with every other instance past level 50 until Outland. I will admit that I was miserable before the Burning Crusade came out, but that was more of how level 60 was than the path to it.
It saddens me that I will never enjoy Blackwing Lair or AQ40, and atleast until Wrath of the Lich King, Naxx. But the point I'm making is that I miss the exploration of the early levels. And I have tried to make alts, but it is not the same. Is it really the game, or the loss of its innocence, I've been missing so much?
I almost want to find a new MMO that is coming out and play it, where no one else has played it before either. Or try a new game period, I don't know.
Honestly I would love to get a group of friends, make alts and level up with them and do all the instances, the right way at the level you are supposed to anbd without higher level help.