Based on my cursory Googling:
Microsoft keyboards have been broken for a while.
Logitech apparently actually uses 128-bit AES, though the question of how they generate their symmetric key isn't exactly answered in a way that's satisfying.
Not sure about Dell. Couldn't find much on their keyboards with my cursory Googling. They seem to mostly rebrand other people's wireless keyboards?
And Apple keyboards all seem to be bluetooth.