I think it’s Tavatimsa because you can still be mindful of death due to war with the Asuras. You can also offer flowers to a cetiya there and make merit. The sensual pleasures there are weaker than those in higher realms.
Additionally, in the Therāpadāna, as far as I’ve read, most, if not all, who were destined to become enlightened during the time of the Buddha Gotama were reborn in Tavatimsa after performing good deeds and passing away from their previous life, so I think Tavatimsa is a good place to fulfill parami.
The Abhidhamma is also always taught there first and not in any other heaven.