There are only three generally available versions of what is widely regarded as one of Shakespeare's greatest comedies, and all three of them have things to commend them. Two are now relatively easy to find in video format; as always, though, the BBC Shakespeare set is available only through institutional channels.
1936, Paul Czinner: This is the first of Laurence Olivier's many film productions of Shakespeare. Not all of them are, unfortunately, of equal quality, and this is somewhat uneven. Aside from Olivier himself, perhaps the greatest talent in the project was off the screen -- the score is by Olivier's frequent collaborator, William Walton, who also wrote the scores for Olivier's Richard III and Henry V, and the editing was done by David Lean, who went on to become one of the foremost directors of his or any age, scrupulously crafting such works as Lawrence of Arabia and Doctor Zhivago.
The most peculiar and perhaps initially disturbing thing about the film is Elizabether Berger (Rosalind) herself. She came from Austria shortly before the film was made, and she plays the whole with a slight but unmistakable Austrian/German accent. If you can believe that Arnold Schwarzenegger is a middle-American native son named Fred Smith or the like, you can probably swallow this too.
1978, Basil Coleman: This is the BBC Television Shakespeare version of the play. It is nearly complete and it also features some of the best production values represented anywhere in the series -- still far short of a well-produced contemporary film, but eminently watchable. It is filmed largely outdoors, rather than on a soundstage somewhere, and the benefits are considerable, in the direction of realism, rather than abstraction (which also has its points). The forests have real trees, the fires have real flames, and the shepherds have real sheep.
All the parts are covered at least competently, and generally engagingly -- both brothers, both dukes, the various pairs of lovers, etc., are quite good. There are a few standouts, however: the production features an extraordinary Jaques, and also the remarkable Helen Mirren in her prime, in the pivotal role of Rosalind. Her performance (like her Titania in A Midsummer Night's Dream) is subtle, intelligent, and occasionally ambiguously menacing. Rosalind is offstage for much of the first part of the play, and the timing sags and lags a little when she's gone (except in the scenes involving Jaques); but the latter half of the play is energetic and completely involving.
1983, Hirsch/Levine/Roland: The last of these is not even documented on the normally exhaustive Internet Movie Database, though one can find it listed on Amazon (which owns IMDB) as part of the Shakespeare Collection. I'm a little surprised at that, since the film is in fairly wide current distribution. The Shakespeare Collection is a three-play set (including also Romeo and Juliet, 1993 and The Taming of the Shrew, 1988). All three are videotapes made from stage productions at the Canadian Stratford festival. In all three cases, the tape quality is quite poor, with skips and flickers of one sort and another, and a slow-speed color-bleeding image -- but the performances are still quite good. Here, the real winning roles are the always-intriguing Rosalind, and Lewis Gordon as Touchstone. The whole production is strong, coherent, and alive with that peculiar electricity that tends to happen in live stage performance more than on film. It's also cut very little, if at all -- definitely worth seeing, therefore, if you can find it and abide the poor tape quality.
Related:
Small and oblique though it is, it may be worth noting that the recent Drew Barrymore vehicle "Never Been Kissed" includes fairly extensive explicit references, and thematic parallels, to As You Like It. It is a lightweight romantic comedy -- charming and mostly innocuous. It does, however, feature a leading character who is a grammarian, and that's appealing on its own terms.