Harry Morgan on Dragnet and MAS*H
Tom Bosley on Happy Days and Murder She Wrote
Joe Mantegna on Criminal Minds and The Simpsons (voice of Fat Tony)
Valerie Bertinelli on One Day At a Time and Touched By An Angel
Has anyone mentioned John Lithgow yet? 3rd Rock (comedy) and Dexter (drama)
His characters always seem to be in varying shades of gray. He seems to be very rarely an outright good guy or an outright bad guy. I think the only thing that ties his characters together is he usually plays someone who only does things in his own best interest. Which some times means helping the good guys even if he’s a bad guy. I think the closest he’s come to being an outright good guy is in Doctor Who, and even for a while there we were misled into thinking he was bad.
Edie Falco played Carmela Soprano (in The Sopranos) and Celeste Cunningham (30 Rock). I haven’t seen her in Nurse Jackie but I imagine her role there is also a far cry from Carmela Soprano
Amy Ryan was Beatrice ‘Beadie’ Russell (on The Wire), and Holly Flax (The Office).
I haven’t actually seen his appearances in Dr Who, and have only seen about two episodes of BSG, but every other show I regularly watch seems to have him appear in at least one episode as a bad guy or at least, as you say, someone who only does things in their own interest, usually opposed against characters who are trying to help people.
Seriously - pretty much all the shows I’ve regularly watched over the last few years will have Mark Sheppard show up playing Badger from Firefly but under a different name. (Tricia Helfer usually has an episode as a hard-arsed bitch too). Hence my impression of him having this defined role.
In Leverage, for example, he’s morally gray in some ways, but he’s against Our Heroes, and some of his actions cross over the line into bad guy territory.
For example, getting the Leverage crew incarcerated is just his job; choosing the worst possible prisons to send them to is unabashed sadism. And he uses Nate’s son’s death against him. All after he knows that they’re helping people.
Hmm, he was set up as pretty bad in his first appearence, where he seemed perfectly happy to let the innocent stable owner go to jail.
“We’re insurance men, Nate. We don’t care about who’s guilty and who’s innocent. We care about who pays.”
You missed out a series which I liked, but never made it to dvd or even the torrents: LA Dragnet. Ed was the star though they kind of put him into the background in the later parts of it.
I haven’t read the entire thread (sorry) - has Hugh Laurie been mentioned? great range from a twit in British comedies to bastard on House.
Yes he has.
How about David Schwimmer, best known as hapless Ross on the sitcom ***Friends, ***but a hard-ass Army lieutenant in the WW2 series Band of Brothers.
Did anyone already mention Jack Klugman, star of the comedy The Odd Couple and of the medical/police drama Quincy?
Or Buddy Ebsen, of ***The Beverly Hillbillies ***and Barnaby Jones?
Jere Burns was in 90 episodes of Dear John and is now in the FX drama Justified.
I thought I was the only person that remembered Frank’s Place. I loved that little one season show SO much!
Psych has a few actors that have been in Dramas: Dule Hill (West Wing), Tim Omundson (Deadwood), Corbin Bernsen (LA Law), Maggie Lawson (Party of Five).
Maggie Lawson was on Party of Five? Wow, I did not know that. I only ever watched the show when reruns were up on OnDemand a few years ago, but they only showed part of the series and must not have included ones with her.
Andy Griffith - AGS & Matlock
William Shatner - TJ Hookers, Star Trek, and I would argue that much of his recent TV work is very comedic, but, not on a sitcom.
Bleep My Dad Says may have been a lousy sitcom, but it was a sitcom all the same. 
He was so funny as The Big Giant Head on 3rd Rock From The Sun
So funny he got an Emmy nomination for it, even.
But it wasn’t successful. 