If you leveled a character up to 60, did a few raid instances like Stratholme, Scholomance, BRD, UBRS, Onyxia, and Molten Core
My issue with WoW became essentially that -- once you're L60 all of the instances become massive time sucks. It takes several hours to do any of the above (excepting, perhaps, Onyxia -- but merely getting the key for her takes several multi-hour expeditions in BRD), which is a drastic departure from the previous gameplay, even in instances (Maur could take several hours if you do the entire thing, but each "section" only takes 60-90 mins).
I simply don't have that kind of time... I have maybe two hours a night to play games. More than that and I'm eating into sleep.
So my account is cancelled now... I guess I could've restarted a new character and explored the world that way, but I really wasn't interested in doing that. Blizzard could've restructured the high end instances to be doable in shorter chunks, but it seems like they explicitly decided to do the exact opposite.