It's a great question...
Norths were as good as Canterbury in 94 but died in the butt again come finals time. And Canberra battled injuries all year in 91 and the fact they made a 3rd consecutive GF was incredible, but again Norths were along with Penrith the best two sides in 91 over the season. If you narrow it down to just regular season then 2001 has to be a chance with parra and newcastle, 2002 very similar as the Warriors were minor premiers after all (if we ignore the Dogs but i don't think you can), last year Canberra were among the best teams for most of the year but failed at playoff time.
Like I said tough question... if I rewind the mind back to the seasons I can recall..
1992 - Broncos and Dragons ranks up there although Illawarra were a genuine force that season and were a few double movements from the Grand Final instead of the Dragons.
1990 is the year I reckon from my viewed grand finals that stacks up the highest, as the Panthers and Raiders were the two best followed by the Broncos. And the Broncos made the Final so that's probably the best year for the favourites/best teams making the end trip.
I missed being old enough to store the great Parra/Dogs rivalries of the pre 1987 years but from what I have read and been told - they were the years when the best sides truly dominated (throw in a Dragons team here or there!).
Sadly as we are all aware - the fabled Broncos v Raiders Grand Final of the 90s we all hoped for never happened... the closest we got was in 1990 when the Raiders and Broncos played in the preliminary final and Canberra were simply amazing winning 32-4. My history might not be 100% accurate but Canberra and Brisbane have only played in x finals games.
1990 = Preliminary Final #1 Canberra 32 bt #2 Brisbane 4 (Canberra won title)
1993 = Minor Semi Final #5 Brisbane 30 bt #3 Canberra 12 (Brisbane won title)
1995 = Qualifying Semi #2 Canberra 14 bt #3 Brisbane 8 (neither team won title)
Amazing stat esp since everyone wanted that to be a Grand Final - and over the 1988 to 1998 period when both teams had their core of superstars they only play 3 times in Finals. In a word:
Disappointing.