The Real Time host can't help but crack a genuine smile when Joan is around, the fellow comics reuniting here at HBO's Golden Globes after-party in 2006 at the Beverly Hilton.
Joan visits the hirsute star of Bengal Tiger at the Baghdad Zoo backstage in March 2011. After Williams' death, Joan said, "Everyone remembers him as a brilliant comedian but he was much more than that. He was an extraordinary actor and very generous in spirit. I cannot remember a time that we were together that he didn't make me genuinely laugh. He was one of the nice guys."
Both looking stunning in black, the divas lean in for a photo op at the 2011 Critics' Choice Movie Awards at the Hollywood Paladium.
The Venezuelan-born fashion icon goes glam with Joan at the Fabergé Big Egg Hunt Cocktail Countdown on Jan. 28.
Twinsies! Joan cuddles up with the biggest diva of them all.
The Fashion Police co-hosts toast to another great year of their show.
The BFFs catch a Broadway show in 2012.
Joan is one of the parade of celebs who owes Jimmy $100 and is forced to pay up on Feb. 17 after losing a bet that he would never host The Tonight Show.
Matchy-matchy! It must be cold inside Dennis Basso's Fall 2012 show on Feb. 14, 2012, at Lincoln Center during Mercedes-Benz Fashion Week.
The Family Guy star and his longtime love bring Joan into their modern family at the February 2013 launch of their Tie the Knot spring collection of ties.
Joan brushes up on her Shakespeare backstage at the Richard Rodgers Theatre in November 2013, where Bloom was starring in Romeo & Juliet.
The Fashion Police pals are all smiles at New York Fashion Week together in 2012.
Looking '80s-hair-tastic at the Fourth Annual March of Dimes Gourmet Gala in NYC on Nov. 4, 1991.
Artistic types: Joan attends the opening of Rosie's exhibit "Solace: An Exhibition of Paintings" at NYC's World Stages in October 2007.
Just a couple of gals who aren't shy about doing what it takes to look their best, full of yuletide cheer at a Christmas party in Beverly Hills.
The comedians catch up on the set of Bravo's Watch What Happens Live.
Rivers and Winfrey go all the way back to January 1986 when Rivers interviewed Winfrey on The Tonight Show Starring Johnny Carson!
The red-headed comedian was an outspoken fan of Rivers.
Rivers and Kors pose together at the Fifi Awards in June 2001.
Joan has some fun with her seatmates at Dennis Basso's Fall 2013 show during Mercedes-Benz Fashion Week in February 2013.
A longtime friend of Trump's, Rivers won season eight of his show The Apprentice!
The mother-daughter duo were each others' biggest fans.
MORE PHOTOS: 2014's fallen stars