I haven't played since a little after Uldaman (sp?) came out. It got stale. And way too easy.
I think the regular high end dungeons should be easy and provide decent blues. Then the Heroics should be fairly tough and provide really good blues, with maybe 1 epic on the last boss. Then RAIDs should be really hard and even with full top end epics not be some easy ass stroll, except for really good guilds or whatever.
They also allowed the scrubs into everything. No more getting keyed for heroics or raids. On one hand, I certainly see why and I think it's great opening more content to the more casual gamers, but on the other it made it painful for people that wanted to find a good group and not wipe because half the party is in lvl 78 greens.
Anyway, for me, since it was so much easier I was able to get all the good Heroic loot and PuG most of the raids to get all the epic epics too. I had a prot warrior with like 39k HP (barricade of eternity) of the a and a dps deathknight using Black Ice and usually was top 3 dps even in 25 man raids.
I also didn't like how unbalanced PVP became. It was really fun at lvl 60 and even lvl 70 in the BC expansion... lvl 80 PVP was stupid IMO.
So then I turned to crafting. Mining + Black smithing on my warrior... I rarely mined though, just used it for titanite. According to the stats page I averaged 3200g income per day. Basically I bought all the stupidly cheap saronite from the farmers, then crafted all the lvl 78 gear - blue quality swords, shields, axes, daggers, maces, dps plate, tank plate, pally plate etc plus as many titanite epics as I could. At any given time I had around 100-150 pieces on the AH... I ended up with a Mechano Hog for both my characters plus a Traveller's Tundra Mammoth for my warrior. I quit with 20k gold on him, which was going to be for a second mammoth.
Anyway, at that point I thought - fuck this, I beat the game. And I am a much happier person without MMOs.