Wintergrasp was amazing; the full scale war attitude of it, the vehicle combat, the RP-GGs flying overhead, the huge mobilization... as I said, amazing. There were two of us that would always lead Wintergrasp... I would command things up North, and the other individual would head the forces taking down towers... it was great. Having a set server with a level of continuity and community about it meant that people would respond and listen to people they knew could competently command. I actually had people say as much in post-battle Wintergrasp chat.
I spent so much time there, I got 48,000 kills in Wintergrasp alone.
Tol Barad on the other hand... I don't miss. No real strategy, no way to gain actual footholds in victory (other than time with the towers...) Honestly, they should have just taken WG layout, made it look tol-barad-y, stuck it in Cataclysm and called it a day.
It's somewhat of a shame that they don't have a similar area in MoP.