Who are some of elite sub woofers?

I’ll speak up for SVS as well...whether "elite" or just for the downtrodden masses. They definitely improved overall sound quality of my system. I’m running a pair of SVS SB1000s (sealed, 12", 300 watts) each located just inside a floor stander (Totem Forests or Silverline Prelude Pluses). I hear none of the issues millercarbon mentions. Apart from the blue LEDs being on, you don’t know they are until switched off. The bass they support is seamless with the main speakers, nuanced and textured...hardly "one note" and definitely not boomy. With a 45 day in home audition option, a 5 year warranty and "free" shipping (even on the return if you don’t like them) they’re worth at least considering.

SVS subs are not "elite" because they are priced fairly and are of high value, something so-called elitists care nothing about.

The Audiokinesis Swarm is one of the best subwoofer systems out there. Most do things like 'bass in the room but not at the listening chair' due to standing waves in the room; the Swarm solves this problem (provides uniform bass at all frequencies) while at the same time being relatively unobtrusive.

Why sealed or ported? Personal preference or is there better sound?

I was not trying to be a snob by saying elite! I was afraid high end would get 4 figure costing subs. I don’t want cheap just to have a sub or two.