To watch a lot of local television news is to appreciate just how good a reporter is Mark Londner. Viewed side-by-side against his competition, the Channel 7 senior correspondent's story is likely to be the most thorough and the most balanced. Londner simply digs deeper to add the context that television news stories so often lack. Also excelling, in different ways, are WPLG-TV (Channel 10) political dean Michael Putney and WAMI-TV (Channel 69) upstart John Mattes, who displays welcome investigative acumen.