>>67864586a bit of a recency bias, but the one with Aruran was great since it had a mix of a goofy set up joke (kinda like the one in Gura's bday concert) and it picked a song she was already part of, which also happens to be an amazing track
non-recency bias, it'd be Aki's musical themed bday concert, especially her part in the final group song being incredibly cute and showing her off as a competent dancer
if you count it as a Live 3D appearance, the Countdown performance with Watame and Bae might fucking take it tho