The classic: Mae West - Wikipedia
I have a girl crush on her.
What about Brooke Shields?
After seeing her in the Last Seduction, she can never be funny, or trusted, again.
Man, she was good in that.
Also, IIRC, Karen’s abrasiveness – in the Will & Grace universe – was very much a coping mechanism. After a few seasons, they’d show Karen letting her guard down from time to time.
Hell, the Grace character in Will and Grace… “I just always imagined being proposed to while I was holding a bouquet of flowers, not my own ankles”… Had me rolling.
I only saw two acts (on Youtube), but Rita Rudner was quite funny and quite the hottie back in the 1980’s.
How about Loni Anderson in “WKRP in Cincinnati?” We’ve been making our way through the Season One DVDs and she has a number of killer lines in that show while also being THE blonde bombshell on TV at the time (I think Farrah was pretty much gone from “Charlie’s Angels” when 'KRP hit the airwaves).
Kristen Johnston as Sally Solomon on 3rd Rock From the Sun.
I think I may have mentioned my desire for a Jon Stewart/Craig Ferguson sandwich, with me as the filling. 
Those two guys have not only the double whammy (good-looking and funny), but a triple-whammy - they’re smart as hell as well.
Jennifer Tilly!
Allison Hannigan
Tea Leoni
Minnie Driver in “Good Will Hunting”
Rosario Dawson in “Clerks 2”
Sigourney Weaver in “Ghostbusters” and “Galaxy Quest”.
No one mentioned Barbara Eden in her prime?
I think we’re focusing on women because you mostly focused on them in your OP, Robot Arm.
I’ll second Maura Tierney and Vicki Lewis from Newsradio, but my goodness, how can one not mention Khandi Alexander as well? And I don’t even swing that way. Jennifer Aniston and Lisa Kudrow from Friends. (Courtney Cox doesn’t seem especially sexy to me, but I’d imagine she does to others.)
Kate Hepburn in The Philadelphia Story and Stage Door. Ginger Rogers in Stage Door. Young Eve Arden always played ‘best friend’ roles but I think she was quite striking. Seconding Bernadette Peters and Madeline Kahn and Teri Garr – the Mel Brooks trinity. 
How about Felicity Huffman and Sabrina Lloyd in Sports Night? For those who remember older BBC shows, there’s Felicity Kendal in Good Life / Good Neighbors. (And some may find Penelope Keith dishy as well.)
On the male side: James Stewart and Cary Grant, also from The Philadelphia Story. Grant was very funny in Arsenic and Old Lace and Mr. Blandings Builds His Dream House, too.
Young Desi Arnaz was hella hot in ILL. Hugh Grant is deliciously funny in Four Weddings…. Alan Rickman brings droll humor to almost every role and I defy you to find five consecutive women on the intrawebs who don’t think he’s sexy, despite his non-traditional looks. Ted Danson was pretty yummy back in Cheers.
Of course, Stephen Colbert, Jon Stewart, Steve Carrell, Ed Helms, Craig Ferguson. John Kraszinski. Rowan Atkinson in the second and third seasons of Black Adder. Hugh Laurie in almost anything. Young Michael Palin, especially in Holy Grail. Peter Davison as Tristan in All Creatures Great and Small was extraordinarily cute and charming.
And for reasons I can’t quite understand or explain, David Dixon as Ford in Hitchhikers Guide to the Galaxy and Richard Coyle as Jeff in Coupling, God help me.
Diana Rigg - Emma Peel from the Avengers
Rosalind Russel
I’m an oldie.
Yes, yes, a zillion times yes!
Crystal Bernard in Wings
Jennifer Aniston
Goldie Hawn
My entries: Jeanene Garofolo and the woman whose name I cannot currently recall from the British version of Whose Line Is It Anyway?
RR
I missed the edit window, but the WLIIA woman I was thinking of is Josie Lawrence. Yum.
This far and no one mentions Marilu Henner in Taxi?