What's your favourite Arduino model, past or present?

I will always be a fan of 32 bit flat memory models. Self modifying code is just not practical with a Harvard model. Unfortunately, I have not had time to play with my Due so I don't how it stacks up against my other boards.

Teensy 2.0 is my favourite.

I appreciate the Uno had some technical improvements, but at the cost of losing some of that pleasing simplicity.

How so?