My favourite times of the day are:
Breakfast time, lunch time, dinner time and bed time!
Oh and lets not forget Miller time! heh heh! :D
No but seriously, being a perennial sun-dodger I love the late night/early morning...
From about 3am, after most of the local drunks have finally stumbled home; to 7:30(ish)am, just as the sun's come up and everybody else is getting ready to go to work still drunk or with the beginning of a mighty hangover.
You can't beat seeing a good sunrise before going to bed on weekends!
And my favourite time of the year is the autumn/winter..'cause the night is that bit longer! :)
This varies so much, depending on what I am obsessing about currently:
The night sky at 4:00 am at 12,000 feet;
The sunrise through the mist over a lake;
A few fleeting clouds in a blue sky that recedes to infinity seen at noon from the shade of a tree;
A loud, raucous punk bar after 4 beers and midnight