Lena Dunham and Jenni Konner's millennial masterpiece Girls comes to an end on April 16, with Hannah Horvath (Dunham) probably moving away from New York City to have her baby — leaving her friends Marnie (Allison Williams), Jessa (Jemima Kirke), Shoshanna (Zosia Mamet), Elijah (Andrew Rannells) — and ex-boyfriend Adam (Adam Driver) behind in the process, which will be a happy ending.

Throughout its run, the always-provocative show drove conversations about race, class, feminism and sex, and not always because of its on-screen action. But Lena Dunham the public persona is different than Lena Dunham the creator, and her show never faltered on delivering showily well-written and sneakily well-directed comedy-drama that always felt different than anything else on TV.

Girls did many things extremely well — its taboo-busting treatment of sex and nudity may end up being its greatest legacy — but nothing was more fun than its masterful deployment of guest stars. Dozens of brilliant character actors and future A-listers appeared on the show over the years, and the show used just about all of them well, no matter how small the part.

What Will the Legacy of Girls Be?

Here are the 15 best.

Lena Dunham and Patti LuPone, <em>Girls</em>Lena Dunham and Patti LuPone, Girls

15. Patti Lupone

Lupone was hilarious as herself in two Season 3 episodes. Hannah interviewed her for an article sponsored by a bone density drug, despite Lupone not having osteoporosis (or a French bulldog named Pippin). She dropped a ton of wisdom, inspiring Hannah to keep following her creative dreams.

Jemima Kirke and Ben Mendelsohn, <em>Girls</em>Jemima Kirke and Ben Mendelsohn, Girls

14. Ben Mendelsohn

One of a weirdly high number of actors to appear on both Girls and in a Star Wars movie, Mendelsohn showed up as Jessa's negligent father in one Season 2 episode. It was a small part but he nailed it, playing Salvatore as a fun hang but a terrible parent who made perfect sense as one of the things that made Jessa the way she is. And he helped bring out one of Kirke's single best performances in the series.

Richard E. Grant, <em>Girls</em>Richard E. Grant, Girls

13. Richard E. Grant

The veteran British actor appeared in a handful of Season 3 episodes as Jasper, Jessa's friend from rehab. He sort of embodied her problems with her father and offered a crystal ball glimpse at her future if she stayed on the path she was on. He's also the only character to ever out-fast-talk Shosh.

Bob Balaban, <em>Girls</em>Bob Balaban, Girls

12. Bob Balaban

The owlish Christopher Guest favorite appeared three times in three seasons as Hannah's therapist Dr. Rice, and each time we learned something new about him that made us wonder if he's the right guy to be treating her. His children's books do sound cute, though.

Allison Williams and Jorma Taccone, <em>Girls</em>Allison Williams and Jorma Taccone, Girls

11. Jorma Taccone

This Lonely Island member showed up in Seasons 1 and 2 as an unbelievably douchey artist with whom Marnie had a fling. Their relationship ended badly when Marnie realized he thought of her as his assistant. We still can't get the image of his naked body starfished out on top of Marnie on his studio floor out of our heads.

Lena Dunham and John Cameron Mitchell, <em>Girls</em>Lena Dunham and John Cameron Mitchell, Girls

10. John Cameron Mitchell

Hannah's unfiltered ebook editor met a bad end, drowning in the Hudson River in what may have been a Grindr date gone wrong. But before that, he made us laugh with lines like "Hannah, did your hymen grow back?"

Donald Glover, <em>Girls</em>Donald Glover, Girls

9. Donald Glover

Glover was brought in as a love interest for Hannah in Season 2 after the first season was criticized for being too white. He elevated what was a borderline token black character part with his hilariously annoyed breakup, telling Hannah she couldn't deal with who he was — a black Republican who didn't like her writing.

Lena Dunham and Jenny Slate, <em>Girls</em>Lena Dunham and Jenny Slate, Girls

8. Jenny Slate

Slate appeared on two episodes, one in Season 1 and one in Season 5, as Hannah's college rival Tally Schifrin. In Season 1, she was publishing a book and making Hannah jealous. In Season 5, they had a chance reunion, where Tally confided she was miserable. One of the constants of Girls is that no one is ever happy, no matter how their life looks on the outside.

Riz Ahmed and Lena Dunham, <em>Girls</em>Riz Ahmed and Lena Dunham, Girls

7. Riz Ahmed

Ahmed appeared in two Season 6 episodes as Paul-Louis, an affable but painfully unserious surf instructor who unwittingly got Hannah pregnant. He's technically the father, but he's relieved to find out that Hannah doesn't expect him to be involved in the child's life. He's the epitome of those classic Girls guys who seemed nice at first but turned out to be just as awful as the rest of them in his own way.

Gillian Jacobs, <em>Girls</em>Gillian Jacobs, Girls

6. Gillian Jacobs

Jacobs had a Season 4 arc as Adam's artist girlfriend Mimi-Rose. She was sort of a bizarro-Hannah, independent where Hannah is needy but still insecure in similar ways. She had one of the show's most memorable breakups, declaring that she chose "herself" when given an ultimatum between Adam and her ex-boyfriend Ace.

Jemima Kirke and Zachary Quinto, <em>Girls</em>Jemima Kirke and Zachary Quinto, Girls

5. Zachary Quinto

Speaking of Ace, he was maybe the single least-likable character on a show filled with unlikable characters. Everything about him, from the toothbrush he carried as an affectation to the calculated way he made his spite-girlfriend Jessa, Adam and Mimi-Rose's lives miserable, was offensive. He was your worst conception of a Brooklyn hipster come to life. And Quinto had so much fun playing him.

Lena Dunham and Patrick Wilson, <em>Girls</em>Lena Dunham and Patrick Wilson, Girls

4. Patrick Wilson

Wilson appeared in "One Man's Trash," one of three unforgettable Girl-and-a-male-guest-star bottle episodes that feel spiritually connected. In that Season 2 episode, he played Joshua, not Josh, a separated 42-year-old doctor with whom Hannah had a brief fling in his beautiful brownstone. He was different than Hannah in every way, and his presence changed what Hannah imagined her life could be, at least for a moment; "Please don't tell anyone this, but I want to be happy," she tearfully told him. He briefly appeared again, unexpectedly and amusingly, as the doctor who tells Hannah she's pregnant.

Matthew Rhys, <em>Girls</em>Matthew Rhys, Girls

3. Matthew Rhys

The other Hannah-and-a-man episode came in Season 6's "American Bitch," where an older, more experienced Hannah visited the apartment of successful novelist Chuck Palmer, played with cunning charisma by Matthew Rhys. Palmer was upset with an article Hannah wrote criticizing him for hooking up with college students, and he invited her over to talk about. They had a searing discussion about the complex and distressingly unfair sexual politics between powerful men and young women. And then he took his penis out. It's one of Girls' best episodes, a statement of purpose that times are changing and women will not be silent about mistreatment by powerful men anymore.

Shiri Appleby, <em>Girls</em>Shiri Appleby, Girls

2. Shiri Appleby

Appleby played Natalia, Adam's girlfriend during a time he and Hannah were broken up in Season 2. Her arc culminated in "On All Fours," Girls' most controversial episode and probably its best, when Adam subjected her to a degrading sex act that's one of the hardest-to-watch scenes in TV history, just behind Marnie singing "Stronger" at her ex-boyfriend's work party, also in this episode. It was an incredibly brave performance from Appleby that changed the course of her career — it's hard to imagine her getting the lead role on UnReal without this.

Christopher Abbott and Allison Williams, <em>Girls</em>Christopher Abbott and Allison Williams, Girls

1. Christopher Abbott

This one was a shocker. Christopher Abbott played Marnie's on-again, off-again boyfriend on Seasons 1 and 2 before leaving the series over conflicts with Dunham over the direction of his character. So it was a huge surprise when he showed up in Season 5 for blast-from-the-past fling with Marnie. He was like a totally different person, and then it was revealed that he was now addicted to heroin. Abbott got the send-off he deserved. Even more shockingly, the episode made us feel sympathy for Marnie. Taken as a whole, "One Man's Trash," "American Bitch" and "The Panic In Central Park" make a case that Dunham's next TV project should be an anthology series where something different happens every episode. She's great with one-offs.

Girls' series finale airs Sunday, April 16 at 10/9c on HBO.