I haven't seen all these choices (most egregiously having missed Swank in Boys Don't Cry), but I opted for Barry Humphries (so supremely witty and charming as Dame Edna), Dustin Hoffman (disappeared into the role of Dorothy), and Terence Stamp (lovely understated performance as the fearless Bernadette); Barbra Streisand as Yentl is also quite good, but I didn't see her disappear into the role like these other performers.
My very favorite drag role isn't listed here--Tim Curry as Dr. Frank N. Furter in The Rocky Horror Picture Show. Dynamic actor/singer making an unforgettable film debut in a challenging role.