Actors who had unforgettable guest-starring roles on ‘Will & Grace'

Here is the late, great Debbie Reynolds as Grace’s mother, Bobbi, doing the Adler family “told ya so” dance. That’s not from her introductory episode, but it’s definitely unforgettable.

Molly Shannon’s Val is a character that is pure absurdity, insanity and, well, danger. She’s great. In her first episode, “Grace, Replaced,” she literally tries to replace Grace as Will’s best friend (and basically as Grace Adler). Oh, wacky neighbor Val.

In the late, great Gregory Hines’ first episode as hotshot lawyer Ben Doucette, he refuses to pay Grace and then ends up convincing Will (you know, Grace’s best friend…and lawyer) to join his firm. (Then eventually, he tap dances on the show. And also dates Grace.)

The late, great filmmaker Sydney Pollack (“The Way We Were,” “Tootsie,” “Out of Africa,” “The Firm”) played Will’s philandering dad, and…that’s pretty cool. Objectively, it was pretty cool. Series co-creator David Kohan was apparently Pollack’s assistant for a time, and then he got the (pretty cool) opportunity to ask him to be part of his own show.

Joan Collins guest stars as a rival interior designer to Grace in this episode, but the most important moment is when Collins’ character, Helena Barnes, scarfs up a taco with the help of her tiny dog. (Well, that and another mention of Karen’s alias: “Anastasia Beaverhausen.”)

Though it was only three episodes, in the year 2000, Patrick Dempsey’s arc on “Will & Grace” (as Will’s closeted boyfriend, Matthew) really helped to shine a light on Dempsey and his career in a post-’80s  “heartthrob,” post-’90s “recognizable guy who’s always just kind of around” world. In 2002, he would be the guy Reese Witherspoon didn’t choose in “Sweet Home Alabama.” Then in 2005, he would become “McDreamy.”

Appearing as herself, Cher ran into her biggest fan, Jack…and Jack absolutely blew it.

“Lows in the Mid-Eighties” is an all-time great “Will & Grace” episode, but arguably the funniest bit of the whole flashback experience is Karen chiming in to explain what she was doing in the 1980s (separate from literally the entire Will/Grace/Jack drama). She was apparently breaking hearts when she decided to settle down with Stan…and tennis player Martina Navratilova’s heart was one of them. The IMDB description for the Karen part of this flashback episode says it all: “We also learn why the famous tennis player Martina Navratilova became a lesbian.” It was because of Karen.

Sandra Bernhard guest-starred as herself on Will & Grace, and in her initial episode, Will and Graced posed as "wealthy dot-commers who don't have kids" interested in buying her townhouse, only to then attempt to befriend her. Bernhard would return the following season as Will and Grace were actually in the market for a new apartment, kicking them out for cursing her — as she had been able to sell her townhouse — in the first place.

Beverley Leslie may be Karen Walker’s “dearest white friend,” but he’s also her greatest (though not largest or tallest) societal rival. His initial episode, “My Uncle the Car,” sees him stealing Rosario’s maid services from Karen — and the two of them eventually playing a game of pool to settle this score. In the original series finale, he was part of the best moment of that episode, when a gust of wind blew him off a balcony.

As Nathan, Woody Harrelson brought a different — very heterosexual — energy to “Will & Grace.” He and Grace were definitely an “opposites attract” type of couple, and honestly, that opposite attraction was never quite replicated at Grace and Nathan’s breakup.

As baked into the DNA of the series as she may seem, Blythe Danner’s role as Will’s mother and ultimate WASP, Marilyn Truman, somehow wasn’t introduced until the fourth season of the series. (Will’s father was, of course, introduced two seasons before that.) But she first appeared in one of the best episodes of the series — a “Will & Grace” Thanksgiving episode— which was the perfect way to introduce her once it finally happened.

The thing about Nick Offerman as the plumber in this classic “Will & Grace” episode is that it was totally a forgettable “guest starring” role…until Offerman became a notable actor due to “Parks and Recreation,” and he and Megan Mullally became a Hollywood power couple. Which is why it’s OK that Offerman has since returned to “Will & Grace” (in the revival) as a separate character — with a name and everything.

The end of the third season saw Jack meet his son, Elliot (Michael Angarano) — the result of a sperm bank donation — and the fourth season eventually saw Rosie O’Donnell as Elliot’s mother, Bonnie. A famous lesbian playing a lesbian on “Will & Grace?” That happened, you know.

“A desperate Jack seeks to "in" his rival for the last spot in the Manhattan Gay Men's Chorus that will tour Europe by dangling a motivated Grace as date-bait before him to prove that he's actually straight.” In this case, Matt Damon plays Owen, the aforementioned rival who Jack attempts to “in” and prove is actually straight… which he does. But come on, of course Jack still loses to Owen. All thanks to this unforgettable sing-off.

Michael Douglas appears in this episode as Gavin, a detective who uses the case of Will’s stolen laptop as an excuse to spend time with him, as he’s afraid to just ask out Will directly. Obviously the episode title and premise were based on the Michael Douglas/Glenn Close film “Fatal Attraction,” which brings us to the next episode of the series’ fourth season...

In “Hocus Focus,” Glenn Close plays Fannie Lieber, a riff on famous photographer Annie Leibovitz. When Will gets a free photo session with Close’s Fannie, he and Grace end up struggling to take a picture in which they both look good...until Fannie plants the idea of them having a baby together in their head, that is.

Poor Harry Connick Jr. A charming guy in pretty much every other place — you’ve seen “Hope Floats,” right? — he had trouble translating that into the character of Leo. And then the show just started writing Leo as far less than the Prince Charming he was introduced as and, arguably, the biggest mistake Grace ever made...yet she somehow ended up with him (which is one of the myriad reasons why the revival undoing the original series finale will always be a good thing). But you can’t say Leo was a forgettable character. Sorry, Harry Connick Jr.

Kevin Bacon (as himself) is the object of Jack’s stalking and even ends up hiring Jack as his personal assistant…to find out who’s been spying on him. Naturally, Jack ropes Will into all of this, leading to Will and Kevin Bacon doing Kevin Bacon’s “Footloose” dance from the Kevin Bacon movie “Footloose.”

Depending on who you ask, Karen Walker’s greatest rival is either Beverley Leslie or Lorraine Finster. For the latter character, serious actress Minnie Driver got to play Stan Walker’s borish mistress and — in her introductory episode — a possible threat to the Karen/Jack relationship as well.

2003 was a good year for Demi Moore: She starred in “Charlie’s Angels: Full Throttle” and appeared as Jack’s former babysitter on “Will & Grace.” Most people will never have a year as good as that — and they won’t deserve to because they weren’t in “Charlie’s Angels: Full Throttle.”

James Earl Jones (as himself) looking to “Will & Grace’s” Jack for acting lessons? The comedy obviously writes itself. (Actually, “Will & Grace” writer Gary Janetti wrote the comedy,)

The argument for “Will & Grace” to have ended at its sixth season: Other than how off the rails it became in its final two seasons, Bobby Cannavale’s Vince (introduced this season) was also the last major character introduction in the original series run that really worked. An Italian-American cop (who was also sweet and, you know, gay) probably isn’t who Will saw himself ending up with… but let’s be honest, that’s probably who Will should’ve ended up with.

The shift from “still OK” to “absolutely insane” happens for the show between the Season 6 finale and the Season 7 premiere, and J. Lo (playing herself) is the only true constant — other than the actual cast — between the two.

Luke Perry playing a nerd? Yup, it happened — and it happened seven seasons into “Will & Grace.” (His character was really into bird watching, and Jack was really into him.)

Fascinatingly fun fact: Comedy legend John Cleese was uncredited for all six episodes of “Will & Grace” he appeared in. His character, Lyle Finster, spawned Minnie Driver’s character though, and that’s really the greatest credit of all.