I started looking for a microcontroller that I could play with as
a hobbyist.  There are a few attributes I wanted:

1. Parts readily available.  I used the Digikey catalog as they have many
   families of controllers available and they're a great distributor.
2. Parts readily available in DIP packages for prototyping (see my banner).
3. Reasonably C-friendly instruction set.  I used Z-80 in college and it
   has an instruction set designed with C in mind.  That's what all those
   SP-relative instructions are for:  accessing stack frame variables.  I got
   an 8-pin development board, and it did something known as not working.
   I don't know if it was a bum steer or what, but I couldn't get a program to
   load into the flash and run.  Besides, Zilog's website isn't real efficient at
   telling you in detail what the differences between the processor families are.
   I heard Microchip's lab emulator was good and reasonably cheap.  But as anybody
   who's written PIC assembly knows, banking and paging bits will be your bane.
   I like this quote from the PIC vs. AVR smackdown (I fixed the English):
   
   Overall, I've written some asm for both processors and I hate to
   break it to PIC users but writing assembly for PIC is akin to stabbing
   myself in the face. [Except it's not even that efficient, because you have
   to more the knife into the working register first (movlw KNIFE), and
   then you can stab yourself (movwf FACE).]
   
   I just didn't feel like spending a third of the flash memory flipping those bits.  Not to
   mention a fixed 4 or 8-level stack that only holds addresses, not data--oh just forget it.