I'm younger, so I basically grew up on Fracture, MRR, and assorted UK zines. Of the decade just past, I'd say the best zines were Club Stupid (hands down the best straight edge zine ever)/Pushed Your Luck, Murder Contest and Max Mitchell's ...Blue zines.
On the other hand, and this is a discussion I've been having recently upon "downsizing" my zine collection by about 95%, I think the constant eulogising of zines does tend to ignore the fact that for every half decent one, you went through 10 mind bendingly awkward zines with regurgitated anrchism rants and interviews with bands that seemed to take a page and a half to say "Who are you, where are you from, how did you meet, what's playing in a band like?" I love zines and long may they continue, but you'd get the impression from the internet in general (since the real thing are as rare as hardline advocates at hardcore gigs these days) that the "zine era" was devoid of cruddy zines. I think buying really crap zines is as much of a rite of passage as buying your first mid/late80s Boston hardcore record.