Meryl Streep and Diane KeatonHow better to show your love for Diane Keaton, then to dress up as one her most iconic characters? At last night's AFI Lifetime Achievement Award honoring Keaton, Meryl Streep donned a suit and tie a la Keaton in her Oscar-winning role in 1977's "Annie Hall."

Keaton and Streep played sisters in the 1996 film "Marvin's Room." Can we get these two legends in another movie soon?

Also among the guests: All of Keaton's famous exes, including Warren Beatty, Al Pacino and Woody Allen, who made a rare appearance in LA for the occasion. Considering he usually skips the Oscars, even when he's nominated, that's a big deal, as evidenced by the gasps from the audience.

Allen joked, as Showbiz411 reports, "I didn't know much she loved me until I read her book -- and that she was bulimic. I took her to all these $400 meals when we were together. I could have saved a lot of money and taken her to Pizza Hut!" He also knocked her famous fashion style, saying, "She looks like the woman in 'A Streetcar Named Desire' who comes to take Blanche away."

Rachel McAdams, who costarred with Keaton in "Morning Glory" and "The Family Stone," shared the best advice the acting veteran gave her: "Get an assistant, don't be too picky with men, and always wear your nicest underwear. I did, I'm working on it, and I'm wearing Spanx, I failed you there."

Among the other stars paying tribute to Keaton: Emma Stone, Reese Witherspoon, Steve Martin and Martin Short.

Per Variety, Keaton threw away her prepared speech saying it was all too much. "Tonight is astonishing. I am not going to give a speech." Instead, she sang "Seems Like Old Times," as she did in "Annie Hall."

The event will air on June 15 at 10 PM ET/PT on TNT.