Baby-Face Nielsen

Before he hit parody pay dirt as Lieut. Frank Drebin, Leslie Nielsen labored as the earnest dunderhead in dozens of ''serious'' movies — all of which, post-Police Squad!, seem irresistibly funny. Take his 1956 starring debut, Forbidden Planet, newly reissued on laserdisc. As a spaceship commander determined to rescue a scientist from his telekinetic subconscious, whatever that is, Nielsen is utterly Drebinaire. He's forever whipping out his utility-belt mike to bark commands like ''Artificial gravity off! Cut primary ! coils!'' while lusting after the scientist's sexpot daughter (Anne Francis).

On the old cassette version, Planet's wide-screen picture is cropped, lopping Nielsen off many shots. But MGM/UA's new disc is letterboxed, salvaging every second of Nielsen proto-shtick. The $24.98 disc looks as sharp and almost as colorful as the $100 Criterion version issued two years ago. The new release is part of a laudable MGM/UA line of affordable discs (which includes the somewhat more serious 2001: A Space Odyssey).