If a good newscast is aired in a sensation-drenched market and nobody watches, did it really happen? While you're pondering that one, tune in to WAMI at 10 p.m. on a weeknight for The Times. Though often uneven, The Times never suffers from a lack of ambition. Better yet, the show displays that rarest of TV-news qualities: a sense of humor. Although anchor Ben Mankiewicz gives viewers the stern anchor eye when a story calls for it and can talk policy with the best of them, his bemused smile and self-deprecating attitude are truly refreshing. The great thing about Mankiewicz is that you're never quite sure if he's being serious or if he's sending up the whole TV-news genre in a sort of meta-newscast that's half Peter Jennings, half Dennis Miller. Definitely the kind of guy we'd like to have a few beers with.