I started with the 6502, but my second computer was an Atari STE and did a lot of 68k programming. It was great. Then I discovered the book "The Art of Electronics" as a late teen. It had a whole bunch on the 68008 ( which is gone from the current edition ) which was nice for little embedded projects as it interfacedd with the 8 bit world.

https://en.wikipedia.org/wiki/Motorola_68008

later on I got to do some work on a 68030 series micro. That was pretty nice also. All assembly based.