The curtains will close tonight on David Letterman's 33-year run as a late-night host.

Comedians and fellow talk show hosts have been paying tribute to Letterman ahead of his retirement.

Check out some of the funny, heartwarming and downright bizarre tributes below.

Jimmy Kimmel:

Jimmy Kimmel gave a tearful tribute to Letterman, remembering how he used to stay up late to watch his show. 

“It was weird, even though it looked like every other talk show, it wasn't,” Kimmel said. “It was totally original, primarily because the host of this show, who a lot of the time seemed embarrassed to even be there, he did not seem like he was a part of show business, he was uncomfortable, he never pretended to be excited, and his way of saying things was so subtle that a lot of the times, the people he was talking to didn’t know he was joking.”

Kimmel recalled how his mother baked him a “Late Night” cake when he turned 16, and he showed off a photo of himself in front of the ‘L8 Nite’ vanity plate on his first car.

Kimmel told viewers that the reason he has a show of his own is because ABC executives saw him on Letterman’s show and hired him. He told viewers to watch Letterman’s last show tonight instead of “Jimmy Kimmel Live,” which will air a re-run.

Jimmy Fallon:

Jimmy Fallon praised Letterman’s “innovation, fun and just plain weirdness” in his tribute to the “Late Show” host, adding that “The Tonight Show” is a result of Letterman experimenting and exploring with the genre.

Fallon also remembered how Letterman was the first late-night host to come back on the air after the 9/11 attacks.

Fallon quoted Letterman’s monologue from that first show back, where Letterman told viewers, “There is only one requirement for any of us and that is to be courageous, because courage, as you know, defines all other human behavior.”

“That is so nice,” Fallon said. “We needed that. David Letterman is courageous."

Stephen Colbert:

When Letterman first announced his retirement, his successor Stephen Colbert had some funny things to say about the “Late Show” icon.

He recalled when Letterman’s show debuted during Colbert’s first year of college, telling the audience, “I learned more from Dave than I did going to my classes — especially the ones I did not go to because I stayed up until 1:30 watching Dave.”

He quipped, “I do not envy whoever they try to put in that chair.”

Jon Stewart:

Jon Stewart said that he “fell in love with the joy” that “The Late Show” brought him through the years.

“There are so few people that can innovate that format. And then to be an innovator with longevity, I mean, damn. The list is Dave. I think the list is Dave," Stewart said.

Watch his remarks and an old clip of Stewart and Letterman in the video above.

Tina Fey:

Tina Fey was recently on “The Late Show,” where she pledged she would never wear a fancy dress on a talk show again after Letterman retires.

So, she decided to give her final dressy dress to the outgoing talk show host, stripping down to her Spanx and a leotard that said “Bye Dave!”

Bill Murray:

Nobody had a sweeter goodbye than Bill Murray, who popped out of a giant cake to send Letterman off.

He stumbled out of the cake wearing goggles and enveloped Letterman in a very messy hug.

Watch the hilarious clip above.

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