Valium with a doubt!
And was told by my pain management doctor yesterday...the same thing!
However, I also know there are other kinds that might work well for someone else. For me, they are ALL like eating candy OR they have SE's like heartburn, etc. But for muscle spasms caused by inflammed nerves...it is Valium all the way. And it is what my NS ALWAYS prescribes after spinal surgeries.