This isn't even specific to MMORPG's. Any group oriented game varies a lot on the quality of the people playing. It's fantastic when you're in a tight and competent group and it's hell when you feel surrounded by morons. Admittedly WoW does aggravate this a little because many of the people are new players (especially on the alliance faction) and have become used to the "easy" solo mobs. So moving into an instance forces a mental jump that many of them don't come close to making. On the positive side, and unlike EQ, at least corpse recovery and the "death by group" penalty are quite light.
I've done ragefire chasm, wailing caverns, shadowfang keep, black fathom deeps and razorfen kraul so far, mostly with guild groups, and must say they're some of the finest dungeons in any MMORPG. Complex design, story elements, good loot and some interesting tactical challenges. Wailing caverns, while perhaps a little long, is beautifully finished by the event at the end that gives a real sense of completeness.
Is a man not entitled to the hurf of his durf? - Simond
I fucking hate Blackfathom deeps. Water dungeons are complete bullshit, have been that way since zelda, and will continue to be so, forever and beyond. Fuck blackfathom deeps and it's stupid shit.
I had fun with deadmines, though, despite having to do it multiple times because of dipshit pickup groupmates paving the way for my deaths, target dummies that fail to function 90% of the time, and general life-related obstacles to my digital crack.