Used to be everyone learned assembly in college.
I imagine that was x86, which was relatively easy but also horrible. Very few people are writing assembly today because you'd need to be able to do x86-64 SIMD, ARM64, and maybe RISC-V, which are all quite a bit more complicated.
We learnt MIPS assembly as part of the processor design class, where we built a DLX processor & emulated it running our code, and then we learnt x86 assembly as part of a class on debugging & reverse engineering (which is also where you'd usually have the good old bomblab assignment). That was in 2014.
Everyone else is saying MIPS, but we learned Motorola 68k Assembly. Which I suspect was mainly because we had a bunch of dev boards for it. It was fun starting off by toggling the lights, using the switches to make a primitive binary calculator, before leveling up to making programs than communicated over the serial port.
It was MIPS for me, which isn't widely used in industry, but it did the job.
MIPS, because of the books provided for computer architecture (Hennessy and Paterson) were written by the MIPs designers. No one I knew of learned X-86, the Dragon compiler book however had all its examples in VAX assembly.