Mine would be Mill Creek, or anyone else who includes silent Alices and Aesops in their PD releases.
Mill Creek isn't just a PD company now. They've released licensed DVD's of TV series (individual seasons and complete series sets) and licensed DVD's and Blu-rays of movies. Most of what they've released so far is Columbia/Sony properties, but they even managed to license movies from Disney. (Albeit movies like
Ernest Goes To Camp.)
Some of the TV series Mill Creek has released on DVD:
BewitchedI Dream of JeannieMaudeThe JeffersonsSOAPThe Cosby ShowMiami Vice21 Jump StreetMarried With ChildrenRoseanneWingsThe NannyThe DIC Heathcliff series
The DIC Dennis the Menace series