I'm looking for something with an interface similar to MS debug.exe

I would like to invoke it with debug MyELF
Be able to dump register
Trace commands

Also, I'd like to run it with no args, so that I can assemble stuff immediately to test snippets

linux comes with gdb you might have to install it from the RPMs if you didnt select it on install of your os

I tried gdb. It is definitely NOT designed for the assembler language programmer.

As far as I can tell, you can't even assemble code with GDB.

ALD is a little better, but it also sux.

goto http://linuxassembly.org this is the best starting point foe assembly programming under linux and yes thay have links to assembly debuggers
for linux and more