Through nine seasons of sailing the laugh-track-backed romantic waters of primetime TV, The Love Boat welcomed a lot of celebrity guest stars. In fact, more than a thousand famous names hung out with Capt. Stubing, Doc, Gopher, Isaac, and "your cruise director," Julie. And the long list is a diverse one, including future Oscar winners Tom Hanks and Kathy Bates, Mr. and Mrs. Brady (and Alice), George and Weezie Jefferson, future TV superstars Courteney Cox and Michael J. Fox, Menudo, Dolly Parton, Reggie and Janet Jackson, the Dallas Cowboy Cheerleaders and the Harlem Globetrotters, Anderson Cooper's mama (designer Gloria Vanderbilt), and the late, great Andy Griffith, Vincent Price, Andy Warhol, and Milton Berle.

Oh, and Betty White.

The 92-year-old Emmy winner (and national treasure) guest starred in five episodes of The Love Boat (including one with her late husband, Allen Ludden), so she knows a thing or two about guest stars.

Especially how to attract them.

White is, unsurprising to anyone who's a fan of the much-beloved TV legend (i.e., everyone), one of the main reasons celebs today are lining up for guest gigs on her sitcom Hot in Cleveland, the TV Land hit that's rivaling The Love Boat with its lineup of celebrities who've popped in for a visit.

"It's just like the best thing ever," says Tim Daly, star of the CBS fall drama Madam Secretary and current Hot in Cleveland guest star. "[Betty] is a such an example and an inspiration for everyone. She's 92 years old, sharp as a tack, really funny, and a great actress. And as a human being, she's just a darling woman."

Adds recent guest star Morgan Fairchild (whom White's Elka hired to portray her in a play Elka had written): "She's just so sweet, and she's so funny. She's been in the business so long, and I love talking to her about her experiences. When I was [filming with her], it was right after her birthday, and someone had sent over a tiger cub for her to pet and play with for a little bit. She knows I'm an animal nut, too, so she sent her assistant down to my dressing room to get me so I could play with the tiger cub, too."

White's HiC co-star, Valerie Bertinelli, says she and fellow Cleveland-ers Jane Leeves and Wendie Mallick appreciate the cachet — and guest stars — White attracts to the show, too.

"Yeah, that's the factor right there. It's kind of obvious," laughs Bertinelli. "I'm very proud of my work, and I think Jane and Wendie are amazing. They have amazing backgrounds and talent. But let's be real: It's the Betty White thing. When you have Betty White as a draw, you're going to get anybody in the business. Everyone wants to come and meet Betty, and then we get to play with them, too."

Among the guest stars who've spent time with the Hot in Cleveland women so far: Mary Tyler Moore, Carol Burnett, Don Rickles, William Shatner, Cloris Leachman, Jimmy Kimmel, Tim Conway, Regis Philbin, Joe Jonas, Melanie Griffith, Heather Locklear, Huey Lewis, Ed Asner, Chris Isaak, Sandra Bernhard, Fred Willard, Jesse Tyler Ferguson, Eddie Cibrian, John Schneider, Doris Roberts, Valerie Harper, Jon Lovitz, Susan Lucci, Jennifer Love Hewitt, Shirley Jones, Wayne Knight, Georgia Engel, Buck Henry, Joan Rivers, George Hamilton, David Spade, Cybill Shepherd, and Kristin Chenoweth.

With no end in sight for the TV Land comedy, which is currently airing its fifth season, that list of guest stars will only continue to grow. Todd Milliner, who — along with Will & Grace star Sean Hayes and series creator Suzanne Martin — is a HiC executive producer, says a dry-erase board in the Cleveland writers room has a list of guest stars show whom the cast and crew want to pursue, as well as a list of famous names who've made it known they'd like to make a stop in "The Cleve," as Jack Donaghy so memorably referred to the Ohio city on "30 Rock." And, he adds, White's co-stars bring in plenty of famous names themselves.

"We're blessed to have people want to do the show," says Milliner, also an EP on Grimm and Hollywood Game Night. "We talk about that. You know, I think early on in a show, you don't want to be The Love Boat; you want to spend a lot of time with the four regulars. But then eventually you get these great guest characters to come through, and these great guest actors.

"We have a cast of four people that… this isn't their first hit. We got really lucky that these ladies, just by the nature of their previous jobs, have got people that they want to come work with again, and who want to come work with them. It's fun for us and the fans to see John Mahoney reunite with Jane, while playing a Betty love interest. To have Carl Reiner, who is very close with Betty and [was with] her husband. There are all these personal relationships that [we can make] fit into the story, and they want to come play. We don't have to twist any arms."

Bertinelli says she was particularly grateful to reunite with her One Day at a Time co-stars Pat Harrington Jr. and the now-late Bonnie Franklin on Cleveland. "I'm so blessed that I was able to work with her one last time," she says of her TV mom, who died in 2013. "Bonnie always was incredibly kind to me, and she always treated me like a daughter… to this day she holds a very, very special place in my heart, and I miss her."

Milliner and Bertinelli both say they've been trying to find the right story line to bring Bertinelli's other One Day at a Time family member — her sitcom sister Mackenzie Phillips — to the show as well. "Yes, yes, yes, yes. We almost had a part for her in the first season, but [the role] was a little bit too odd," the actress says. "Because it was going to be a rock star that I was in love with, and we had to kiss, and we thought, 'Hmmm, it'd be like sisters kissing — that might not work.' We're still trying to come up with a great story line for her."

Also on Bertinelli's wish list: Elton John (whose "Don't Go Breaking My Heart" she and Phillips performed in a classic One Day at a Time scene), a return visit from Hayes (a choice Milliner seconds), and George Clooney, after whom the resident dog on Hot in Cleveland is named.

"If George Clooney was holding George Clooney, that would be even better," Bertinelli tells Yahoo TV of the Oscar winner, who worked with White on an episode of The Golden Girls, and Leeves in an episode of the short-lived '80s sitcom Throb.

"I'd love it to be a really meta-episode, where [Clooney] came on the show and was upset that that was the dog's name," Milliner says. "I have luckily had a lot of people that I wanted on the show, a lot of my friends… Chris Colfer just did an episode, and Max Greenfield has done a couple of episodes. Dave Foley, who continues to reoccur, and Tim Daly. I'm sure Jane would like to work with David Hyde Pierce again, but he's always doing a Broadway show. Maybe one day, we can twist the arm of Eddie Van Halen to come on if there's a rock 'n' roll story."

As for the other reasons celebrities are drawn to the Hot in Cleveland set, many —like Daly — welcome the chance to flex their comedy muscles, especially in front of a live audience.

"You know what? It was like looking in my closet and finding an old suit and going, 'Oh, look at this,' putting it on, and thinking, 'Wow, this still fits me really well,'" the Wings alum, who also did a guest arc on The Mindy Project last season, says. "I'm looking in the mirror going, 'Not only does this fit me, [but also] I still look pretty damn good in this thing.' Because the live situation comedy is quite a specific medium, and not everybody can do it. I remember on Wings, there were some amazing actors that were on the show who couldn't do it. They got fired. They were wonderful actors, but they just couldn't do that thing, because you have to go fast, and you have to understand what the material requires. I feel really fortunate I'm someone who can do that. It was really just so much fun to be able to step back into it and do well, and have a good time with those ladies."

Saturday Night Live alum Nora Dunn, who portrayed the play version of Malick's Victoria in the July HiC episode that featured Fairchild, was happy to get the chance to hear the audience's reaction live. "With comedy, it's really fun to have an audience. You do takes and retakes and all that stuff — but there's something really just kind of bright and even nostalgic about performing for an audience in a studio, because they don't do it that much anymore," says Dunn, who is also reprising her guest role as Ari and Mrs. Ari's therapist, Dr. Marcus, in next summer's Entourage movie.

The show's guest cast also cite the fun, welcoming environment that the Cleveland cast and crew has created for the set ("They're what I like to call 'no-sh--ters. They work hard, and they like to have a good time," Daly says), as well as the no-nonsense schedule of working on the TV Land sitcom as reasons a Hot in Cleveland guest gig is a dream job.

"I'm used to working 60 to 80 hours a week [on Glee]," Chris Colfer said in a recent interview with TV Fanatic. "I think the longest day we've had [at Hot in Cleveland] is four hours, so I didn't know what to do with myself when I got home. I could easily get used to this."

As for the rest of Season 5, which wraps on Sept. 17, Daly will continue his guest spot as Joy's (Leeve's) love interest, Mitch, and play a big part in what Milliner and Bertinelli hint at as being a season-ending cliffhanger that Daly says he hopes will lead to the continuation of his role. Craig Ferguson returns as Joy's baby daddy, Simon, and both Foley (as Joy's boss) and Bill Bellamy (as Elka's political rival) continue their guest spots, while Queen Latifah plays Bellamy's aunt in the Aug. 6 episode "Strange Bedfellows."

And then there's another Beverly Hills, 90210 alum on the way. Following an appearance by Jason Priestley earlier in the season, Bertinelli says 90210-er Luke Perry made her laugh extra-hard while filming a role for the Sept. 3 episode.

"Some of these people who came on the show, they think they have to do one thing, and then when they get on the set… like Luke Perry, who had the funniest bit," Bertinelli says. "I can't give it away, because you just have to see it, but he was in heaven. He was so sweet, and so handsome, and he was clearly having a great time."

Hot in Cleveland airs Wednesdays at 10 p.m. on TV Land.