There's no real "right or wrong"... Around here, we tend to like Nasm :) But you could use (G)as with the ".intel_syntax noprefix" directive, and write Intel syntax for Gas, if you wanted to. Fasm, Yasm, and HLA run on Linux, too (with ".intel_syntax" available for Gas, HLA is the one with the "weird syntax" :) I don't think you'd go wrong by using Nasm, but there are lots of choices!
Best,
Frank