World of Warcraft, as much as anyone wants to bash it, is the most complete game on the market. It has something for everyone and more content then any game since the original EQ. The problem is they keep making it easier. Our history starts back on Stormreaver in OG with cyrk. A few of us played in OG for a while before leaving WoW to go back to the CU in SWG.

Some Pre-BC action via Cyrk's OG

Blackwing Lair
Nefarian - Horde First Ahn'Qiraj
C'Thun - Horde First Naxxaramus
Patchwerk - Horde First

In BC some of us came back to WoW. We brought a solid core transfered to Korgath to help rebuild Overrated. Within a couple weeks we had all content cleared and we had illidan on farm. It was fun for a while but the game had nothing left to offer us so we moved on to AoC before sunwell released.

Some BC clearing Screens via Psypher in Overrated

SSC
Lady Vash - Fury Warrior Deeps Black Temple
Illidan - Pimp Slapped Zul'Amon
ZA cleared - Bear Mount style

For WolLK we made the move back to stormreaver and cleared all content in a couple weeks and then got bored quickly and moved on to Global Agenda beta testing. The problem with WotLK is it is way too easy. All the content was pugable within weeks of release which should be considered a major insult to anyone that paid for the expansion. Blizzard really welfared out on development, hopefully ICC will be better.