To kick it off, I’ll pick Mr. Plant.
(Les Paul called him–on the night we were both in the audience at Fat Tuesday’s–"Bobby Plant")
There’s Yogi Bear’s little sidekick Bob Alooey.
You’re thinking of Quick Draw McGraw and Baba Looey.
Baba Looey doesn’t count as a Bob. Neither does Mr. O’Riley. 
Bob Newhart, the king of sit-coms.
You beat me to it. I haven’t seen them in concert for a few years, though. Sittin’ in Limbo came up on my iPod the other day and I was trying to remember how many Bobs there have been.
I hereby cast my vote for childhood favorite Bob McGrath.
Do fictional Bobs count? If so, then I’ll say Sideshow Bob.
What about Bob Ra Ann?
Bob Keeshan (Captain Kangaroo)
Bob Barker
and of course Bob Hope
Old Bob list:
Cummings
Barker
Mitchum
Montgomery
Young
Taylor
Q. Lewis
Walker
Wagner
But the main Bob is Bob Dobbs.
What, no mention of Spongebob?
My father used to tell me that when he was a young man, people would tell him he looked like Robert Taylor: http://images.google.com/imgres?imgurl=http://www.leninimports.com/robertaylor01.jpg&imgrefurl=http://www.leninimports.com/robert_taylor.html&usg=__aEJeLEQvgWDbNVZ58pLkc8AEPuU=&h=445&w=350&sz=35&hl=en&start=11&um=1&tbnid=hRB1Ac18BhA6fM:&tbnh=127&tbnw=100&prev=/images%3Fq%3Drobert%2Btaylor%26ndsp%3D20%26hl%3Den%26sa%3DN%26um%3D1%26ie%3DUTF-8.
(Sorry about the long link.)
Looking at his photos, I can believe it. There was a resemblance.
But when I was around, he didn’t look like Robert Taylor. One time we were shopping and a lady asked for his autograph. She was thrilled at the prospect of meeting Walter Matthau.