For me
Jack Kemp died a month or two ago.
John Glenn
Sophia Loren
Art Garfunkel
I know, I normally would have said he was alive and lost the bet. Re Borgnine and Channing I’d have bet they were dead.
Well, considering that I actually lost money be being so sure Robert Palmer was still alive, I’ll say him.
In '05 I was visiting my mother and there was a game show on. The question listed some celebs and the trick was to decide who was alive or dead. I had not known (then) that Maclain Stevenson had passed on.
Up until yesterday, when I read the “Whose death would eclipse Michael Jackson’s” I would have put money on Walter Cronkite being dead.
Abe Vigoda. 
Actually, pretty much anyone.
I just mentioned him to a friend as someone that is still alive. I do not believe that she believed me. That man was ancient when I was a kid and I’m no spring chicken.
Abe Vigoda is alive
http://www.abevigoda.com/ffb.php
Yeah… we know.
Billy Mays.
I was unsure, as recently as this morning, whether or not Johnny Carson was still alive.
Others:
Kurt Vonnegut
Neil Armstrong
Either of the Smothers Brothers
Gallagher (the comedian who, BTW, I didn’t know was alive until he did a show here in town a few weeks ago)
I had long since assumed that Werner Klemperer was dead. Then he was on The Simpsons.
Jimmy Swaggert
Rod Steiger
Jeffrey Tambor
Vivian Leigh
Yep, I thought Walter Cronkite had been dead for years.