Back when I wrote a lot of x86 assembly in the late 90's/early 2000's, I used NASM (the Netwide Assembler). It was the most natural syntax. Very similar to MASM

Back when I wrote a lot of x86 assembly in the late 90's/early 2000's, I used NASM (the Netwide Assembler). It was the most natural syntax. Very similar to MASM and TASM but without the unnecessary cruft (no "dword ptr", etc.) It was a pleasure to work with.