Guest stars if Columbo kept going

Tim Curry would be great as a sleazy high class killer in Columbo, it is like a tailor made role for him.

I'd have loved to see Tim Curry as the killer. That would have been amazing!

I like the names people have come up with. But, reframing the question to stay within the possible - i.e., actors not dead (Alan Rickman), too old (Cosby), possibly too sick (Cosby - eyesight; Tim Curry - stroke in 2012), in jail (Cosby, again), and would do American television (which might rule out Gary Oldman; Curry, J.K. Simmons, Jim Carrey, Sam Rockwell have all done/are doing U.S. TV shows) (I'm not sure Page, or Anna Kendrick - from what I know of her - would make a believable villian; I don't know enough about Alice Eve to make a judgment; Will Smith and Tom Cruise as stated wouldn't do TV - but then again, with their good-guy images, they wouldn't make good villians either) - how about:

James Spader
Lucy Liu
Tom Ellis ("Lucifer")
Kathy Bates
Viola Davis
Sarah Paulson
Jason Isaacs

and Columbo's most challenging villian ever... Betty White (as herself!). He may have all of the evidence, the weapon, the motive and opportunity, but he knows no jury in the world would convict her!

Agreed on Jim Carrey! It could have been quite a surreal episode if Carrey had been given free range.

Anthony Hopkins
Anthony Perkins,

...& Larry Hagman during his prime Dallas days! *

A problem with most of the suggested folks in these posts is that they were too major as stars, some of them were movie stars who didn't do much TV.

Columbo was rather amazing in how it raided the ranks of SIXTIES TV series heroes like William Shatner and Leonard Nimoy(Star Trek), Robert Conrad and Ross Martin(The Wild Wild West) and Robert Vaughn(The Man From UNCLE), and Robert Culp (I Spy.) Patrick McGoohan(Secret Agent, The Prisoner.) These folks were considered, by and large "TV actors" and were affordable even if they had star quality.

And thus, had Columbo continued, the producers indeed would have had to go to TV stars first -- Larry Hagman is a great idea. Perhaps David McCallum from The Man From UNCLE. Perhaps indeed Bill Cosby from I Spy (the producers went on record saying that they DID consider a black Columbo killer -- perhaps James Earl Jones or Sammy Davis Jr -- but decided against it.

Who else was a major TV star of the 60s/70s that could have been recruited?

In the alternative, a few faded movie stars played the villain(like Louis Jordan, or arguably, Roddy McDowall.)

Who would be like that? Peter Lawford , perhaps? George Sanders, maybe? (Though he was dead by 1972.)

I think that Patrick MacNee from The Avengers(British TV show) did a support role where Robert Vaughn was the killer. But perhaps Diana Rigg from the same show , could have been sought to play one of the "lady killers."

That's a good list, and reflects stars of the 70's in a way that the 70's series, for whatever reason, couldn't use. The 70's version kept "reaching back to the 60's" (Culp, Conrad, Marting, Shatner, Nimoy.)

George C. Scott would often do a TV thing(like The Hollywood Squares) as long as his wife Trish Van Devere was hired, too. I wonder if he was considered to co-star in HER Columbo, where SHE was the killer.

Jimmy Stewart DID play a killer way back in the 30's as a young man(in a Thin Man movie); would "Old Jimmy" have taken a Columbo killer role? Perhaps as Ray Milland did?

Fred MacMurray played three great movie villains --in Double Indemnity, The Caine Mutiny , and (worst of all) The Apartment. He'd make a pretty cool "old guy" Columbo villain in the 70's.

Robert Blake is an example of an actor "not suave enough" to play a Columbo villain, I think.

James Garner would have been a hoot -- Rockford versus Columbo. I don't think Garner played any villains until very late in his career.

There were a few "Columbo villains who got away" in the 70's. Ed Asner was originally set to play the commander of the military school in the one that Patrick McGoohan did instead(and won an Emmy for). Orson Welles was pursued to play the killer that Dick Van Dyke played.