Who played Brenda Walsh in 'Beverly Hills, 90210'?

In which TV series is Mitch Buchannon a main character? Who played C.J. Parker in 'Baywatch'? In which TV series is C.J. Parker a main character? Who played Dale Cooper in 'Twin Peaks'? In which TV series is Brenda Walsh a main character? Who played Dylan McKay in 'Beverly Hills, 90210'? Who played Philip Banks in 'The Fresh Prince of Bel-Air'? Who played Carlton Banks in 'The Fresh Prince of Bel-Air'?