The Dave Thomas Comedy Show

Buried in the hexed half-hour that hobbled Newhart, doomed Doctor, Doctor, and provided a fitting tomb for His & Hers, The Dave Thomas Comedy Show is probably destined for obscurity, and that's too bad. Quirky and uneven, this collection of sketches also is a frequently funny, original effort. Dave Thomas is the SCTV graduate who used to do a cutting impersonation of Bob Hope and who, with Rick Moranis, created the beery McKenzie Brothers.

On this new show, Thomas already has added at least two more master impersonations to his repertoire: His embodiment of Edward Woodward in a spoof of The Equalizer called ''The Humiliator'' is one of the year's television high points. Thomas also has cunningly imagined Max von Sydow as a depressed barber. (''I haff been sinking a lot about death lately, the vay some uff us meet bloodier ends than others — a little more off the sides?'')

Thomas is picking fresh subjects for skewering. For all its intelligence, however, The Dave Thomas Comedy Show is awkwardly structured. Thomas' stand-up routine at the start of the show is embarrassingly mirthless, and he chats with each week's guest star on the set, a stylized, old-fashioned luncheonette. This might have seemed like a good idea on paper, but Thomas' movie-star pals, such as Chevy Chase and John Candy, have to perch precariously on soda-fountain stools and eat pie while making small talk. It's a waste of time, and the stars always seem to be groping for more napkins.

Still, when The Dave Thomas Comedy Show is good, it's riotous-funnier than Carol Burnett, tougher than Tracey Ullman. When the show finishes its five-week run, it will likely disappear forever, so check it out now.