It must be a matter of opinion indeed, because all the races that I've seen from 89-91-93 were boring as hell
89 Had the Senna / Prost rivalry. Good battles for the lower scoring positions too.
91 Mansell had some good races in his attempt to catch Senna and some good performances from Berger and Alesi
93 had some good races early on in the season, plus Senna and Schumacher having a few nice battles / fights.
Things that made F1 better for me when I started watching in 1985:
Tracks were better / more interesting
Cars looked better / Not clones of each other.
No massive run offs. Drivers mistakes were punished by the gravel traps. They might as well be racing round some cones in a Tesco's car park now.
No virtual safety car. If you must insist on having a safety car at least have it bunch the field up.
No fake overtaking aids. Oh look, another DRS pass. YAWN!
Unreliability which led to unpredictability
Backmarkers who didn't have to leap out of the way. Remember Olivier Grouillard and Rene Arnoux?
The in-season development.
Special qualifying engines.
More cars on the grid / trying to qualify
Tyre war.
Using whatever compounds they liked.
Spare cars. No need to see your favourite driver out of the race if there's a first lap pileup and restart or a late car problem.
The customer Ford engine, giving smaller teams the opportunity to go racing.
V8, V10 and V12 on track at the same time.
The term "last of the late brakers"
Murray Walker. He could make boiling an egg sound exciting.
Oh, and Moustaches. Drivers had moustaches.
If it wasn't for Max it would have been very dull this year. Comes to something when you've got to rely on a 17 /18 year old newbie to show the established 'stars' how to go racing.