Danmaku Bounded Field, yeeeah! I think that everything past Th08 doesn't have particularly awesome final EX-boss attacks, and Ex-Alice's final is actually one of her least interesting attacks IMO, I love basically everything else in her fight.
HM to Evil Eye Sigma's last phase for DON'T STOP MOVING OMG WATCH OUT FFFFFF-, and Ran's final card (along with Yukari's nearly identical(?) version). Because standing still while a cloud of bullets flies by is awesome, especially when you have to make your own safespot (and often can't, resulting in "how the eff do I dodge this D:")