I'm a relatively new player, so not that many legendary games in my pocket yet. That being said, the most thrilling was definitely a coop match in New Mexico, where I took down 3 BBs and 1 cruiser near the end. I had just learned how to "angle" a few weeks earlier after watching some CC videos, so I was amazed at how effective it was in bouncing enemy shells.
As for my wish, two parts:
Development - alternate US BB tech tree line with all classes not currently in game (i.e. Nevada, Pennsylvania, Tennessee)
Item - USS Massachusetts, the secondaries are OP