The Best x86 Assembler

What does /prog/ think is the best x86 assembler?

I've played with NASM a bit, but I'm about to start a somewhat large project that will be written mostly in x86 assembly, and I want to make sure I pick the best choice.

gas is obviously shit, so I guess it boils down to NASM vs. YASM vs. FASM.

Unlike the rest of the free assemblers GAS actually supports most if not all instructions that exist for x86 and its extenstions
It also have some great debuging instructions and the fact that you can use the C preprocessor/M4/native gas preprocessor with it it's great