At the risk of going off topic - that one is a pure matter of opinion, and depends what you prefer from your racing (close racing and overtaking, technical freedom, good looking cars, pure competition where it doesn't matter if a guy does a good job and wins by a minute - lots of these things tend to conflict with each other). I preferred the late 80s/early 90s to now, that's not a myth, just my opinion, which I realise puts me in the minority.
I agree, to me F1 was better 25 years ago, but that is my opinion and I don't expect everyone to agree, I would also suggest that from what I have read and seen etc, that F1 was even better 20 years before that...
Back to the topic, a few myths I would mention are:
That Ricardo Patrese was responsible for Ronnie's Monza crash...
That Stefan Bellof's performance in his (illegal) car at the 1984 Monaco GP was particularly special given he had the distinct advantage of a normally aspirated car that was also running underweight...
That the 1968 Formula 2 race at Hockenheim where Clark was killed, was a 'minor' event.