If I were in the market for a new sub I would choose:
FI Car Audio Q series - SQ sub that can get loud, detailed and tight, biggest Xmax of the bunch (27mm), options can be added to handle more power, 1000rms, sealed 0.8 to 1.5cuft, $259each /// would choose 1 to be used with a 1000rms amp
SSA Icon - SQL (don't flame me) sub that is built like a tank, has a distinct quick sound to it (can't really explain better), 1000rms, sealed .85 to 1.2cuft, $249each /// would choose 1 to be used with a 1000rms amp
Stereo Integrity New Magnum (not out yet but available in a couple of weeks, I hope lol) - said to be one of the best SQ around, clarity is second to none, Dual2 ONLY, 1000rms, recommened in 1cuft sealed, price around $250each /// would choose 1 to be used with 600 to 1000rms amp.
Image Dynamics IDQv.3 series - SQ sub that can get loud, have a warm sound to it, 500rms, sealed .65 to 1cuft - $299 each /// would choose 2 to be used with 1000rms amp.
Not saying that my recommendation is the best, but I listen to all genre, however more electro, trance, tribal from Tiësto to Sasha to Glenn Morrison, etc...
Hope that helps,
Kelvin