"favourite time" is difficult...
A time in which I would like to live? I honestly think right now is better than any point in the past. Far from perfect but let's face it: Earlier times were crap in SO many regards we cannot even imagine.
I used to be a fan of ancient Greece and Egypt, and they are still interesting to me, but these days I am more into the times that we know more about. There is a whole lot of HUGE holes in our knowledge about ancient times. In medieval times that gets a lot better.
An interesting time indeed!
I tend to say early 15th century is my "favourite" for that very reason. Another reason why that new PC game "Kingdom Come: Deliverance" is exactly right for me btw., being set in 1403.
I also kinda "like" ~400 AD. Stilll a bit of Romans around, and already quite well into the the big Migration Period (~350AD - ~ 600AD) with all the cultural clashes and technological adaption to different kinds of warfare.
...and then the Viking times (~800AD - ~1000AD). Also covering the Moors for example.
....Argh I cannot decide.