The best thing on TV tonight is the hearings -- and I'm not talking about Whitewater. It's the Watergate hearings, part of the territory covered on tonight's installment of "Watergate" on the Discovery Channel.
* "Dave's World" (8:30-9 p.m., WBAL, Channel 11) -- Here's the story / of a star from "Brady" / who shows up as a guest star on "Dave's World" . . . It's Florence Henderson of "The Brady Bunch," who here plays the pushy mother of Dave's wife, Beth (DeLane Matthews). CBS repeat.
* "Murphy Brown" (9-9:30 p.m., WBAL, Channel 11) -- One of the best "Murphy Brown" episodes last year (and there weren't many of them), this repeat stars Wallace Shawn, of "My Dinner With Andre" and "The Princess Bride," as a former member of the "F.Y.I." anchor team. CBS repeat.
* "Northern Exposure" (10-11 p.m., WBAL, Channel 11) -- Because Adam Arkin has signed as a regular cast member of the new fall series "Chicago Hope," he has no plans of returning this season as Adam, the endearingly eccentric recurring character he portrays on "Northern Exposure." So this repeat, in which Adam Arkin's Adam is a prominent player, should be treasured. Also reprising a recurring role: Diane Delano as Officer Semanski. CBS repeat.
Cable
* "My Darling Clementine" (9-10:40 p.m., Disney) -- With "Tombstone" in video stores, "Wyatt Earp" finishing its theatrical run and other movies about the O.K. Corral being corraled up by cable and broadcast networks, it's not too surprising to see the Disney Channel rope this 1946 Western, which stars Henry Fonda as Wyatt Earp and Victor Mature as Doc Holliday.
* "Jim Carrey" (9:30-10 p.m., Showtime) -- Showtime knows it's time to show anything featuring Jim Carrey, and this stand-up solo spotlight special is ready-made for a summer rerun.
* "Watergate" (10-11 p.m., Discovery Channel) -- Third of five parts. Everything I saw in the preview tape of this five-part documentary series was fabulous, but there was this mysterious 18 1/2 -minute gap . . . just kidding. I saw the whole documentary, start to finish, and was fascinated by every minute of it. The names of Woodward and Bernstein pop up for the first time tonight, as does Howard Baker's famous question at the 1973 Senate Watergate hearings: "What did the president know, and when did he know it?" According to the evidence in this program, some of it new, his question can now be answered: "Lots, and early."