I rate the Collingwood team of 2010-11 as good as I have seen them in my 40-odd years of supporting them, so on that score I rate Geelong's 2011 flag pretty highly. So as much as I hate Geelong, I would have to go with them at No.1 for longevity and quality.
Not as good as your 1970 side in my opinion - and i did go to the 1970 second semi and GF - so i saw 1st hand how good that Coll side was
Premierships are full of joy and are the be all and end all - but to me Premierships are a tad overated in judging things
Like last year Geel got Sth Melb - in 1990 Coll got a washed up dads army called Ess
And Rich - the best year in the 4 years streak in my opinion was 2018 - they were clearly the best team - and finished on top of the ladder - and that year they played the Cats late in the year - only won narrowly - but should have won by about 15 goals - i watched in awe of them - they were that good - but they didnt win the Premiership