<u>Gertrude</u>: Does not like David Letterman, Does not like Jack Benny anymore
Solving:
Since we know that <em>Jerry Springfield is Lucy's favorite</em>, he is not longer an option. This leaves George Burn, Jack Benny, and David Letterman.
David and Gertrude do not like <em>David Letterman</em>, so he must be <em>Jose's favorite</em>. This leaves George Burn and Jack Benny
Gertrude does not like Jack Benny anymore, so the only one left to be <em>her favorite is George Burn</em>