HomeTheaterShack has a sub review complete with graphs, done not so scientifically, they do the testing outside.

Most of the review lists I have seen seem to list most of the same ones in different orders with a number of the same ones at the top of the list, so it still comes down to what you like in a sub; meaning you have to hear it in your environment and price.

So what's the first purchase going to be Fred?

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70