African Grays are one of the smartest.
I had an Indian Ringneck.
He was good, named Ringo or Dirty Harry, answered to both: When called Ringo he'd say, "What're doing."
Could whistle the Brisbane Lions Theme Song.
Cough, bark, Lots of talking etc.
When cued by calling him, hello Dirty Harry he would start his routine, " (Wolf whistle), Hello sexy. Go ahead make my night!"
I hand reared him from a naked squab and he grew to be very friendly. Lutino (bright yellow colouring) with a pink neck ring.
I taught him the Dirty Harry routine when I became a single man. Ringo was a good conversation starter at parties.

I even took him to wine tastings.

He sat on my shoulder or on anyone else's he liked.
Cheers Marty