I've only towered for two days, but I'd definitely have to say my most memorable moment so far was stealing Sardon's from Rebellious in no more than 10 minutes and then defending it from them for literally 8 hours straight as they struggled and cheated in every way possible. We finally lost it when we had only 4 people holding and were ready for bed.
An honorable mention goes to the moment seven hours ago when everyone witnessed Envy (the admin in Vintage) take her tag off, set her nick to Player, go invisible, and essentially abuse her powers to take a secured fort and hand it to her guild.
Towers are very fun so far and I plan to do it for a long time. Please take care of the Battle Arena while daddy is gone.