I'd have to say TBC. That's back when everything was a bit more balanced PvP wise (although obviously not completely balanced as the ubiquitous resto druid, SL/SL lock, and MS warrior mix and match bundle would suggest), there was actual difficulty in the raid bosses and we were dealing with major lore characters that we all knew and loved/hated.
To be fair on the last point, Blizzard might have shot themselves in the foot by cramming 4 major villains into 1 expansion and not spacing it out a bit more.
The problems I had with Vanilla were mostly logistical: it was hard getting anywhere, there were long grindy quests everywhere for mediocre rewards (see Scarlet epics that required you to get exceedingly rare drops from the Plaguelands and associated dungeons), and it was a hassle trying to set up and run 40 people through difficult content when 3-4 of them goofing off could kill you.
The problems with Wrath were basically the removal of difficulty in getting gear, rehashing of old content, and extraordinarily simplified bosses when compared to other expansions. Obviously there are exceptions, the end bosses and most of the Ulduar hard modes fall here, but on the whole, the expansion was very, very easy.
Cataclysm was probably my second favorite era, but it got beat out for a few reasons I can name. Firstly, gear was made even easier to get, it was mostly points based rather than the sheer excitement of seeing it drop. Follow that up with the removal of any sort of attunement or dungeon-related epic questline (Argent Crusade dailies tied to the campaign for ICC, the AQ opening as a whole, attunements in BC, etc) made it feel too simple. The dungeon finder improvments (although they were at the end of Wrath I quit playing so I experienced them in cata) completely destroyed any sense of community in the game as you could just queue up for things without thinking or knowing (or getting to know) anyone in the group.
I pretty much don't like any of the new announced changes so my opinion will probably remain the same: the old glory days of TBC reign supreme.
To be fair on the last point, Blizzard might have shot themselves in the foot by cramming 4 major villains into 1 expansion and not spacing it out a bit more.
The problems I had with Vanilla were mostly logistical: it was hard getting anywhere, there were long grindy quests everywhere for mediocre rewards (see Scarlet epics that required you to get exceedingly rare drops from the Plaguelands and associated dungeons), and it was a hassle trying to set up and run 40 people through difficult content when 3-4 of them goofing off could kill you.
The problems with Wrath were basically the removal of difficulty in getting gear, rehashing of old content, and extraordinarily simplified bosses when compared to other expansions. Obviously there are exceptions, the end bosses and most of the Ulduar hard modes fall here, but on the whole, the expansion was very, very easy.
Cataclysm was probably my second favorite era, but it got beat out for a few reasons I can name. Firstly, gear was made even easier to get, it was mostly points based rather than the sheer excitement of seeing it drop. Follow that up with the removal of any sort of attunement or dungeon-related epic questline (Argent Crusade dailies tied to the campaign for ICC, the AQ opening as a whole, attunements in BC, etc) made it feel too simple. The dungeon finder improvments (although they were at the end of Wrath I quit playing so I experienced them in cata) completely destroyed any sense of community in the game as you could just queue up for things without thinking or knowing (or getting to know) anyone in the group.
I pretty much don't like any of the new announced changes so my opinion will probably remain the same: the old glory days of TBC reign supreme.