Here is a classic:
Bob Loblaw.
Lou Grant’s boss? On Lou Grant?
Way too easy.
Close enough to be correct. Art Donovan was the assistant city editor (that is, Lou’s underling) on Lou Grant. IIRC, Lou reported to managing editor Charlie Hume, who reported directly to Mrs. Pynchon, the publisher of the Los Angeles Tribune. Art joined in the daily meetings about which stories would be covered, and writers Billie and Joe would hash out who covered what, while photog Dennis (Animal) Price would go and take photos on-site. But we rarely got to see Art outside these meetings.
“Way too easy”? And I’ve been asking about Art Donovan since page 1 of the thread? Even with the hints, it looks like I managed to stump a lot of people. 
You are correct sir or madam! He placed a microphone in Tabitha’s rattle to steal Darrin’s ad ideas.
You got 'em.
Still have Nero left.
Helmut Spargel
Frieda Claxton
Mrs./Mr. Pommelhorst
Luke Brower
Virginia and Alexander Hayes
Read my post again. I said that Bob Loblaw was way too easy. I only got Art Donovan from your last hint. And even then I didn’t really get him.
Was the actor who played Donovan later on The Six Million Dollar Man?
Yay! I got the Bewitched one right!
I believe that’s the gym teacher on The Simpson’s.
By the way, I believe that someone else answered the Art Donovan question correctly a post or two before the second clue was given.
Okay, I should contribute two for two right answers but I can’t think of anyone. So anyone else can post for me if they wish.
Ahem
Joe Gillis
Gertie
Frank Bigelow
Lars Thorwald
Gertie was Perry Mason’s receptionist. AFAIK, we never saw her. You’d just hear, “Paul Drake is here to see you” and Mason would say, “Thank you, Gertie - have him come in.”
Lars Thorwald was the character Raymond Burr played in “Rear Window.” Cut up his wife and put her in a trunk!
How about Vern St. Cloud?
No takers on Miss Nance yet?
What about Kisa?
Correct on both! Congrats!
Hint on Joe Gillis. He was played by the same actor who played Max Schumacher 26 years later.
Little House on the Prarie, brother of Nellie.
Still nothing on
Alice Knight
John Hill
Richard Baker
I thought these would have been guessed right away.
Wasn’t John Hill the new owner of Melville’s, the restaurant upstairs from Cheers? He was evil to Sam and the gang in a few episodes.
Hardly minor characters. Why don’t you just say he was Cmdr. Shears and be really obvious.
Nope, I’ve seen Gertie appear briefly in a few episodes.