A pre-dawn start for a roughly hour-long flight drifting silently over the Serengeti as the sun comes up, followed by a champagne bush breakfast on landing. It's one of the more expensive add-ons on a Tanzania safari, but consistently rated by past travelers as a highlight.
Balloons launch just before sunrise and are weather-dependent, so flights are typically confirmed the evening before. Because seats are limited and departures sell out, it's worth requesting this when you book your Serengeti safari rather than trying to add it once you've already arrived.