English (UK) accents - Posh, working class, Scottish, Irish, Welsh, Cockney, old seadog/pirate, farmer, pub owner, bartender, footman, butler, stiff upper-lipped army officer.
American accents - Southern, Texas drawl, New York taxi driver, Californian twang, smooth Boston, 1930s mobster, 1950s classic silver screen.
Australian and New Zealand English accents.
Asian accents - Singaporean English (Singlish) with and without foreign words added, Malaysian and Indonesian English, Philippino, Indian English (middle class), Indian English (working class), Japanese, Hong Kong English. Indian English (Northern and Southern Indian accents).
Other foreign accents - French (heavy to mild), German, Italian, Spanish, Russian.
Specific voice effects - drunk, high, just inhaled helium, hallucinating, depressed/suicidal, scared to death, manic-depressive.
Other special effects - Evil maniac laughter, pathetic whimpering, getting slapped/punched, death fall screaming, injury grunting/yelping.
Specific character/actor impersonations (amongst others) - Darth Vader, Obi wan Kenobi, Borat, Sean Connery, Antonio Banderas, Yoda, James Bond, Rambo, Gregory Peck, David Niven, Morpheus, Agent Smith.
Given enough time, I can learn to impersonate almost any voice or accent that I hear, provided a sufficiently large audio word base is provided.