I've seen clips of Gwen, Chita and Liza but in all fairness will not name them as my favorites because I did not have the honor of seeing any of those great ladies in the show.
i was very lucky to see CHITA RIVERA and LIZA MINNELLI play the roles of VELMA and ROXIE in June, 1976, the week it was up for the Tony Awards...GWEN VERDON was out as Roxie due to an injury...I WAS IN GAY-BROADWAY heaven!...and while i really liked the revival with BEBE and CHARLOTTE to me CHITA and LIZA will always be CHICAGO to me...:)
For me, having only seen the revival, I would say Ruthie Henshall as Roxie and Pia Douwes as Velma. For sentiments sake I would also add Chita as Roxie. Yes she was way too old for it ( her line "I'm older than I ever intended to be" stopped the show cold) but it was one of the most extraordinary examples of sheer star quality and showbiz know-how overcoming everything else that I could ever see. She was gorgeous. Also her "Roxie" monologue went on forever.....and it still wasn't long enough
I've seen Chicago several times and while I liked them all very much, the team of Bebe Neuwirth and Charlotte d'Amboise was amazing. I was lucky to be first row center and they were both perfection.
Sandy Duncan was an absolute delight as Roxie. I have yet to see another Roxie in this revival who was played with as much fun and mischeviousness as Sandy did. The night I saw her as Roxie Mamie Duncan-Gibbs was on as Velma (I don't remember if she was understudying at the time or had been promoted to playing the part full-time at that point), and she was very good as well, though, in terms of the revival, Bebe is still the best I've seen so far (I saw her with both Ann Reinking and Marilu Henner as Roxie).
"Noel [Coward] and I were in Paris once. Adjoining rooms, of course. One night, I felt mischievous, so I knocked on Noel's door, and he asked, 'Who is it?' I lowered my voice and said 'Hotel detective. Have you got a gentleman in your room?' He answered, 'Just a minute, I'll ask him.'" (Beatrice Lillie)
"Noel [Coward] and I were in Paris once. Adjoining rooms, of course. One night, I felt mischievous, so I knocked on Noel's door, and he asked, 'Who is it?' I lowered my voice and said 'Hotel detective. Have you got a gentleman in your room?' He answered, 'Just a minute, I'll ask him.'" (Beatrice Lillie)
Donna Marie Asbury and Charlotte d'Amboise were magnificent back in the early 2000s. Would loved to have seen Bebe & Ann or Chita & Gwen, but I'm far too young.
Bebe Neuwirth, hands down, is the best Velma. One of the best musical comedy performances I have seen in 50 years. Gwen Verdon is the best Roxy. Jerry Orbach is the best Billy Flynn. Mary McCarty is the best Mama Morton.
Bebe Neuwirth has been my favorite Velma, with special love also reserved for Ruthie Henshall, Luba Mason, and Ute Lemper. Favorite Roxie was my first, who I saw on tour: Sandy Duncan.