I sort of took this question in a few different ways
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The period of time in MY life that I've enjoyed most is probably right now. Right now things are going well for me and better than ever. It just keeps getting better and better for me.
HOWEVER
If you meant it as "Your favorite period in time to fantasize about living in historically" which is also sorta how I took it, I would probably pick the renaissance period simply because it was the very beginning of what was to come for many worldly innovations. I'd have loved to see all the ancient architecture and scenery from this time period in Europe and would have loved to just explore the world at this time to compare how things have changed and developed greatly between then and now (And we've obviously, as a society of humans, come a long way).
ALSO
If you mean your favorite season (Like favorite period of time in a year); I'd pick the summer. Warm temperatures and cool breezes make a happy dragon
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