My biggest problem was mandatory grinds and steep hills to do a lot things that early cata had along with vanilla and tbc. I prefer to have all challenges instantly available or more or less instantly available and let skill be the deciding factor on whether you succeed, not grinding frost, nature, shadow or fire resist gear and various other pre-requests just to be able to kill a trivial boss with a few mechanics.
Vanilla 5/10 - you had to play spec X when you where class Y or no raids for you in most cases.
BC 3/10 - Seriously people make this xpac always look like its the greatest, it was NOT. Forced to grind to reverred ( no not honored , that was later when it got nerfed ) to be able to enter heroics, retarded. Having to do attunement quests for a million times in your free time to get enough guildies to raid with... Hello LFM Mechanar cause its best badges/hour. Pre nerfed Magtheridon where you had to include 20 or 25 people to click an orb in a fixed rotation or wipe ? Fuck that shit. Vashj ? Guild killer ( whole of SSC was fucking shit if you dont remember it , hydros a heavy resistance fight only to never use that gear again ). Kael Thas ? Guild Killer. Sunwell ? Or should I just call it shamanwell ? No shamans -> Ded guild. Fuck this shit. Also sunwell being released close to or during the summer ? GG there blizz.
Wotlk 7/10 - Clearly the opposite of BC, easy entry level raiding easy and accessible, but for raiding veterans it was just another BT ( killed everything a week or two/three after release, then had to wait for an eternity before the next thing came ). Ulduar was great, so was the invention of hard modes. ToGC was pretty bad and really turned me off. ICC was pretty damn good except it was gated at first and then up for more than a year. Last raiding instance was ????? though.
Cata 8/10 - Really loved the beginning, heroics where really enjoyable for raiders ( they required a bit too much from the average LFD retard to handle though ) , first tier apart from al akir ( retarded RNG hello ) was awesome. Firelands was great despite what people may say about it. DS gave us LFR which was nice for alts to do some raiding in , the fights wherent all that bad EXCEPT for spine and madness, they sure fucked up those two. Also disappointed with the instance traveling all the time here. LOVED cauldrons - too bad they took them out to get some load off raiding guild's officers.
MoP 9/10 - Challenge modes where awesome in the first few months when not everyone had all 3 socket gear making them roflstomp ! First tier was pretty damn good. ToT is a really nice raiding instance as well - although I dont particularly like the reacting to PPM trinkets they are forcing on us. Only downside I have so far is that it has been pretty damn alt unfriendly in terms of raiding. Why bother doing MSV on alts for 489 loot when you can just AFK in LFR and get 502 ? ... I like it they dont give new 5 mans with catch up gear despite the cries of some.
Coming from a guy who has gone to school, worked full-time for the majority of WoWs life(3 jobs at one point), and never pvp's.
Vanilla- 7/10. This is only because I never experienced any of the raid content until well into the 70's(when my pally could solo it).
TBC-5/10. Great design and some smoothing out of gameplay. did not raid this expac due to multiple jobs as well as horrendous Heroic/Attunement gating. this was my money making expac, mostly running SFK for assassin's blades. Also leveled a shammy that expac, had fun- but raiding was just too inaccessible for someone like me.
Wrath-8/10. LFG and Wintergrasp were HUGE boons for me. At the start of the expac I was working three jobs leveled a lock and actually raided some ICC while it was current on all four of my 80's.
Cata-?/10. Started playing Rift with my friends at the time. Came back as Deathwing raid patch was coming out, LFR being a huge reason for my choice. Story was accessible to everyone, but long draught in between content compared to Rift was hard to reattune myself to. it was the same thing on 5 characters for however that god-awfully long period was. If I had to rate it would be 4/10, only because it offered more access to me.
MOP 9/10. Love the idea of even more ways to see the story. My guild is planning on using Flex to build a raid core that is more attuned to normal raiding than LFR. But I do also fear that this will bring about something like what we saw towards the end of Wrath where we wait in a major city for a pug to form. would suggest maybe a separate global channel for players looking to Flex or maybe like old raid finder with a list of people/groups looking for more. Would rather spend my time doing dailies than sitting in a hub.
Also from an aesthetically biased point of view Mists was also my favorite so far with Wrath being a close second. I love eastern culture, and this expac found a great balance for being eastern enough to tickle that fancy but western enough that it did't feel completely foreign. would have enjoyed more anime references(even though the architecture and lore is more Chinese in nature, it would still fit in^^).