I've gotten pretty burned out on MMo's lately too. On the one hand, everything is too freaking easy. They tell you where every quest giver is with giant!!, and there is an arrow or glowing line leading you to completion. SOOOO not what I started out with. On the other hand, I don't have time to spend 5 days figuring out a single quest like I used to. Well, maybe I do, maybe we all do. I mean, I played EQ for almost 3 years and never reached max level. I played other games for years too (DaoC for example), and didn't get bored. Lately, I play an MMO for 1 or 2 months, and I fell like I have completed over 75% of the content. NOT fun.
The only MMO I really enjoyed recently was Secret World. It had bugs to start out, but damn, if you want a challenge, that game is the best MMO in years. Almost, every quest is hard. The voice acting ac cut scenes are spectacular, the story line is engaging and actually makes sense. I did spend hours on single quests, specifically the puzzle styles. I didn't leave the first area for over a month! There is so much to do in each area, and a Horror Genre was so novel, compared to the Fantasy and Sci-Fi dominated MMO Market, it was a total blast. I highly recommend trying it, if you haven't. The dungeons (instances)were also the best I've played in years and years. A few were actually startling and scary! And hard...damn freaking harder than any other recent MMO. First MMO in ages that kept me playing for a long time. I quit after 7 months only because it actually got too hard. I found the Nightmare instances, as a healer, to be too much of a nightmare. Weeks spent trying to learn one boss. I hear they have been tuned down a bit, so I might go back and try it out again.
The only real downer in Secret World is the PvP, which is more like PvE with some PvP tossed in, and not that well done. Much like Warhammer, follow Zerg around from PvE point to point.
Everything else about the game is totally awesome!