[zoren]

If you start with assembly I would suggest not picking x86. I would suggest a RISC or virtual assembly like LLVM. x86 just has too much historic weirdness.

[roskilli]

MIPS is a great RISC instruction set to learn and has a ton of good emulators out there too, highly recommended.

[jbtow]

definitely this. MIPS is a great start for anyone interested in taking the assembly route at any point.

as for simulators i enjoyed using MARS: http://courses.missouristate.edu/KenVollmar/MARS/

[_0ffh]

Like scores of other generation C64 kids by second language (after BASIC) was 6502 assembly. I think it's suitably straightforward. Although the special addressing mode for the zero page might count as a weirdness.

[djmips]

On the other hand, the x86-64 is a lot nicer and you certainly don't have to go very far to find one to practice with.