I started in wrath. Got into the lore of wrath very quickly, which its incorporation of the races and their wars, the scourge, and the titans, made it easier. Questing was engaging and let me get to know the face of my enemy very quickly. Dailies, even though there were quite a few, didn't seem to be as taxing. The token system was a little annoying and over done till they established Justice Points. But, the only "raiding" I ever did, was a 3-hour painfully-slow adventure into Ulduar, only to end up killing Ironscale, XT, and Leviathan and have to quit because our pugs ran out of time. I also did OS a few times. Overall? 8.5/10
Cata was great raiding experience (for me) where I actually got to do some on a regular basis. But the dailies became a pain when trying to balance all the TB and Firelands dailies. The general lore I found to be rather bland, even with the titan and old god aspects to it. It made gearing my main and alts, as well as leveling, quite fast and thus, more enjoyable. I did, however, get very bored until the last couple months before MoP. Overall? 7.5/10
MoP I've had mixed feelings about. Now that I've finally gotten all (except the prince) rep up to exalt on my main, I've been focusing on different reps on my alts depending upon their professions (i.e. my enchanter goes for Lotus, Shado, and Celestials, JC for Order, etc.), which has made the painful rep grinding less arduous. Gearing, however, has been annoying with my frustration at LFR loot (yes I know the system is technically the same and avoids ninja'ing, but the mindset of this annoying system is still prevalent) and the valor cap. Also, despite the shortness of the MoP dungeons, I feel like I'm not even getting nearly enough valor from the runs. Again, maybe it's just a mindset thing. But despite these annoyances, I've been totally immersed in the MoP lore and questing (not dailies) which has incorporated not only new lore, but also strengthened and enhanced the old lore of the Titans, Legion, Trolls, and Old Gods. I've also enjoyed the small bits of PvP incorporated into questing, and the overall war between the Horde and Alliance. Most of us may hate Garrosh for his character, but as our newest scape goat he's been a gift from the gods for storyline. Hopefully, with Thunder King's release, I will be slight less skeptical of this expansion. I believe it has the potential to be the best (for me). So far? 8.5/10