Congo African Greys are great.
I have a smaller version, a Timneh, whose name is Kara (yes... aka KarasXXX). She, of course, has picked up kitty meows and my dog's bark. What's interesting with the meows is that she specifically copies 3 different kitties from my menagerie and has them down exactly. She also says alot of things in my voice. Best is when she calls the cats "Here kitty kitty". I've not counted all the words, sounds, and phrases, but in the 9 years I've had here she's picked up alot.
Love it when I open her cage door and she starts in with "What are you doing?"
I posted here one night a while back about having a conversation with her one night. I knew I'd been up to long when the conversation actually made some sense.
http://www.gofuckyourself.com/showthread.php?t=875833