well, from the point of view of the assembly-programming, the architecture with the best productivity/complexity, when you do assembly by your own hands instead of C compiling something, is Motorola 68000
Unfortunately from the point of view of ISA ... it makes you to cry a lot if you want to create a 68000-softcore in VHDL (too bloated and complex, 2000 orders more complex than R2K)
A computer science course is a trade off of different things, so we had M68K in our assembly laboratory, and MIPS R2K (with/without the pipeline) in our laboratory of architectures (FPGA programming, digital design).
That is good for the theory, for the practice, embedded C programming, real world interfacing and controlling, e.g. PID, motor speed, SERVO, greenhouse … whatever, then PIC32 is the best choice.