In general, they're all good. The RW-12d is the Top Dog of the price point with the BIC, PL-200 a close second.
The SUB-1200 receives excellent reviews and by putting two or three in a room gives one room gain and helps with smoothing out the subwoofer's response to a room's acoustics.
For sales purposes, with the possibility of the RW-12d becoming extinct, the Top Dog replacement may turn out to be the NXG NX-BAS-500 Subwoofer.
There are many fine choices one can make so beyond that of the RW-12d, it's hard to say with certainty which is the best subwoofer. At the next price point level, one can look to the Rythmik, LV12R
. The better quality of subwoofer one can get, the bigger the smile factor.
In the simple, you'll eventually need to make that leap of faith. This is something we all have had to do and no matter, a BIC, PL-200, a Klipsch, RW-12d or a NXG-BAS-500, you're going be happy......well, up to your continued hanging around here, reading up on the possibilities.