I've personally experienced a lion's share of nausea, and the strain I have been growing, CH9 Jack, has definitely helped. I can only really compare it to Mazar-i-Sharif, some local strains, or mexibrick. Obviously, both are FAR better than the mexibrick.
I think the Jack has worked a little better for nausea and the Mazar for pain. Though that is all subjective. But both are strong enough to sedate me if I were to need it. (What does it matter if you can't feel your stomach?

)
Anyway, they're both good, and I'm sure better exists. Good luck on your search!