I'd have to say that it's walking my 2 dogs, Bloke and Lady, in the back paddocks just on sunrise. We've done it every morning since I've owned them (about 5 years) apart from the very odd rainy day or sleep in, Summer and Winter.
It's a truly beautiful time of the day as the glorious sun bathes the ravine scarred sides of the Macdonnel Ranges about 5 k's away in shades of yellow, pale red and burnt orange. The air is full of birdsong and insects and it's nice to amble along, camera and nokkies in hand, observing Nature's morning shift clocking on for the day while the night shift goes home. Contemplation comes easily and soothes the mind.
The dogs enjoy it too, although I can't vouch for what goes through their mind.
My favorite activity and time of day