The thing I would add before I answer this question, and something I've talked about elsewhere on the forum, is that I was introduced to a huge number of films by British television between 1992 and 2001 or so, from the usual Hollywood blockbusters to trashy but fun films like Night of the Comet and Trancers, through to cult films like The She Beast and Jess Franco's eye-popping Female Vampire!
A lot of other UK posters older than I am can talk about the time previous to this when there were probably even more surprising films shown on television (for example I missed many of the early seasons of Moviedrome, and the Cecil B. DeMille or Tarkovsky seasons on Channel 4. Also the little thirty second film at the beginning of the Arena documentary on Mishima's life was the one used to introduce the BBC's early 90s 'Japan season' which showed a number of documentaries and films, notably Kwaidan and Akira for the first time)
I still consider the BBC100 season of a hundred films screened throughout 1995 and the early part of 1996 to celebrate the centenary of cinema as my true 'touchstone' of cinematic knowledge. Beginning with Citizen Kane and ending with the (albeit shorter three hour version) only television showing to date of A Brighter Summers Day, it introduced me to every kind of cinema from all over the world - Stagecoach, On The Town, Discreet Charm of the Bourgeoisie, Hue and Cry, La Ronde, Weekend, King Kong, The Days, Death In Venice, Billy Liar, Badlands, Fury, Andrei Rublev, Ashes and Diamonds, Picnic At Hanging Rock, The Spider's Stratagem, Morocco, Easy Rider, A Farewell To Arms, The Rules of the Game, Written On The Wind, American Gigolo, Aguirre: Wrath Of God, Witchfinder General, The Devils, Claire Denis's Chocolat, Life and Death of Colonel Blimp, Sanjuro, The War Is Over, The Spirit of the Beehive, Ran (and A.K.), Scenes From A Marriage....it helped to briefly sketch in a huge amount of cinema that I've then spent the last fifteen years or so enjoyably filling in.
1995 was a particularly excellent year for cinema on British television because there was also a Channel 4 'Century of Cinema' season which screened the Martin Scorsese film on American cinema in three parts along with most of his big films like Mean Streets, Goodfellas and New York, New York, along with many other classics of American cinema (The Iron Horse, Faces, The Bad and the Beautiful and Two Weeks In Another Town, Forty Guns); a Sci-Fi season (The Brother From Another Planet; THX-1138; the Giorgio Moroder Metropolis; Outland; The Man Who Fell To Earth; I Married A Monster From Outer Space); an anime season; a British 'Century of Cinema' to coincide with a screening of the Stephen Frears Typically British documentary (Sunday, Bloody Sunday; Kind Hearts and Coronets; The Killing of Sister George; Local Hero).
Channel 4 also continued their regular season of premieres of foreign language cinema (from memory I think they showed Mediterraneo; Europa, Europa; Story of Qui Ju; Intervista; Cronos and Jamon, Jamon that year) and their Film on 4 series of in-house productions (that year they showed Raining Stones; Four Weddings and a Funeral, The Long Day Closes, Simple Men and Naked). But there were also one off seasons such as the 'Secret Asia' season (The Blue Kite; Beijing Bastards; Minbo no Onna; Rock 'n Roll Cop), the 'Novel Image' season of book to film adaptations (Naked Lunch; Enemies: A Love Story; The Rainbow; Bonfire of the Vanities; Mister Johnson; The Handmaid's Tale), 'Reel Women' of female filmmakers (Point Break, Blue Steel, Little Man Tate, A Man In Love, Making Mr Right, Gas Food Lodging, even Border Radio!), a Pasolini season (basically everything but the Trilogy of Life, Pigsty and Salo, which I had to wait for the BFI and Tartan DVDs to see), and cult horrors such as The Howling and Dust Devil.
The BBC didn't just have their BBC100 season either. They had a number of spin offs from it (sort of the Eclipse sub-seasons to their Criterion Collection 'mainline'!) such as a Jean Renoir season of both the French and American films, including archive Renoir introductions; a New York season to coincide with the premiere of Taxi Driver that screened The Pope of Greenwich Village, Q-The Winged Serpent and After Hours; a 'Forbidden Weekend' of films and documentaries to coincide with the premiere of The Devils which included Performance, Pastor Hall, Bad Taste, the 30s Dr Jekyll and Mr Hyde, Beat Girl and The Night Porter; the premiere of Easy Rider was followed by Hells Angels On Wheels; a 'Hollywood, Vietnam' season (Platoon, Born on the Fourth of July, Coming Home, Gardens of Stone, Birdy, The Quiet American), and so on. Plus they concluded the year with Sunrise and Hoop Dreams! There was also an Oscar Wilde season to commemorate the anniversay of his trial (The Trial of Oscar Wilde, The Importance of Being Earnest and the 40s Picture of Dorian Gray) and a Hiroshima memorial season (The Shadow Makers, Rhapsody In August and Channel 4 screened Imamura's Black Rain). They even did a season of Idrissa Ouédraogo films and premiered Glen or Glenda with the 'Look Back In Angora' documentary!
Now, I've since picked up many of these films in much better versions than my recorded from television VHS copies, and I totally understand that 1995 as a 'centenary of cinema' year was a special one but I don't think television now could ever match up to the wider decade of the 1990s either. As my dad is often fond of saying, there are more channels but a less of interest on, and I think I would suggest that the lack of innovative scheduling and curating of an ongoing season of films is to blame for this - now UK television is just one-off items of interest, if they turn up at all, and everything has to fit into a certain slot for a certain demographic of audience. That really has lead to a catastrophic decline in quality over this last decade at least.
I just wonder what would have drawn me to cinema if not for television - would I have jumped to import Criterion Collection discs from abroad? Would Masters of Cinema discs have seemed attractive if there wasn't already 'name brand' recognition of various film titles and directors? Is there the same penetration of these films into the consciousness of an audience who never see even a tiny amount of such material on television any more, except on the 'highbrow' channels, and even then only occasionally with lots of disclaimers made about the film having subtitles?
Anyway this self absorbed waffle is to come to the point that very little was exactly new to me about the films Criterion released at the beginning. Criterion interested me mostly because it seemed like they were doing the same thing that I felt UK television was doing in 1995, collecting films together and doing an even better job of it than the BBC and Channel 4 did (for example without Criterion I would never have seen the longer version of Andrei Rublev or the 5 hour version of Scenes From A Marriage). And even now I am a bit more excited about the new areas Criterion might go into now that they have gotten the well known arthouse films out of the way (if I'm being cynical though I'd say that they'll just release them all again on Blu-Ray and that could hold things up!)
To take your Seijun Suzuki example, even Tokyo Drifter (in 1994) and Branded To Kill (in 1999) had been screened on the BBC, the first in a 'Lost and Found' season of rare films and the second in the cult film season, Moviedrome. So those were not exactly unknown qualities to me at the time, though the later Suzuki films (and especially the Nikkatsu Noir box) that Criterion released
were and were bought blind due to the interest that the previous films had raised.
So, to my list of films that I saw first through their Criterion release and maybe would not have seen had Criterion not released them: the Olmi's; Cria Cuervos; Quai des Orfevres (which would have been a shame, since it is a great Clouzot!); Variety Lights and The White Shiek; Tout va Bien (and especially Letter To Jane, which I like even more); The Pornographers; the Rene Clair films; Masculin Feminine; Loves of a Blonde and The Fireman's Ball; The Cranes Are Flying and Ballad Of A Soldier; Tokyo Olympiad; the Hiroshi Inagaki Samurai trilogy; the Larisa Shepitko set and I'm sure there would be others beyond these.
Plus Hopscotch and Koko: A Talking Gorilla
). The only non-Criterion foreign film I have though is La Dolce Vita and I'd love for a chance to do that. 
