Either the 70s or the 90s. Depends on my mood.

Honestly, no decade is ever going to be the "best". The only thing we can hope for is that each one will be a little bit better than the last, but really, it's impossible to be the best since each decade typically comes with its own unforeseen problems.

'70s (rock!) music = best music
And movies like The Godfather I & II, the 1st Star Wars, horror films...
Also I like the fashion the most.

The ‘70s are second only to the ‘60s. A lot of the bands I like (The Beatles, Stones, Zeppelin, Who, Pink Floyd, Doors, Creedence, etc.) formed in the ‘60s. Yes, The Beatles are qualified as a band that formed in the ‘60s. They started in the ‘50s as The Quarrymen, but became The Beatles in 1960, and Ringo joined in 1962. Anyway, the ‘70s were awesome. It had awesome music and good fashion, the ‘80s were pretty good too, the ‘50s and ‘90s were decent, but the ‘60s were my favourite. I love the music, British Invasion and psychedelic. The fashion was amazing. I loved the mods. The hippies were awesome, too. The ‘60s were 3 decades in one.
Early ‘60s (1960-1963): Still the ‘50s
Mid ‘60s (1964-1966) The British Invasion
Late ‘60s (1967-1969) The hippie invasion