Since we are always hating on the automatic here, let's put it in a positive light, at least to some extent. So what is the best automatic you've had the pleasure of not rowing your own gears in?
Personally I haven't driven a whole lot of interesting automatics, my favorite one is probably the 6 spd, 6F55 auto in my SHO. It can handle quite a lot of power (500hp+) and it's never too confused/hunting for gears. It does help that it's attached to powerful motor with an awesome torque curve. It knows when to downshift and it knows when to just make use of that torque and stay in the present gear.
On another note, I am also quite impressed with the 5spd manual that was in my cousins '06 Charger RT, that thing handled the abuse of daily burnouts very well! I know that this a Mercedes derived unit.
I have not yet had the pleasure to drive anything with more than 6 gears, or any of the fancier types of automatic transmissions. I have had the misfortune of owning both a CVT and a 90's VW Automatic.
(pictured, a ZF 8-speed)