My favorite characters were Pooh-Bah (especially as Archbishop of Titipu) and the Mikado. The Mikado reminded me a lot of Disney's Jafar in his cruel-but-happy humor. Katisha was pretty good, though I prefer her to be more angular and haughty and less like a fat old auntie wanting to kiss a struggling nephew.
It's important to remember that G&S built their musicals to be a reflection of "modern" times, and most producers take that purpose for a ride. For this production, they stuck with social commentary and political references rather than cheap shots at specific politicians. Among his other roles, Pooh-Bah was Secretary for Department of Homeland Security. Ko-Ko's list included surly retail clerks, cell phones in the audience (I didn't hear any the whole show), and selling players to the Nationals baseball team. Mayor Fenty was on the list of witnesses for Nanki-Poo's execution.
(Clues for the unknowing -- The Mikado was originally performed in 1885. The setting of Japan was to humor the casual audience's need for "exotic locals" and not in any attempt to emulate or reflect the cultures or politics in Japan. The two racial terms in the libretto have been mostly cut out since about 1910, and they certainly weren't performed last night.)
More information about the G&S Players and the Mikado plot can be found here and here.