choosing a subwoofer

I have spent a lot of time digging through the forums and the articles on this site and I still do not have a good understanding on how to select the right subwoofer for you. It seems like it boils down to preference and that there are many good speakers out there, but there has to be a majority of preference or a small group of speakers that consistently outperform other speakers. I know that there are popular subs for specific applications, such as the W7 for SQ (generally speaking this is a popular opinion). You start with considering how much available space you have and what sort of sound you are looking for based off your musical preferences. Theoretically you could chart out thousands of different applications and have one setup that is perfect exactly for a certain sound, but I think that it would be feasible to have a relatively short list of which subwoofers are best for a general application. I religiously searched through these forums and was unable to find any really good articles that discuss the basics of selecting the right subwoofer for you. Are there any good articles that I missed?

Different subs work well in different enclosures...this should be a big consideration. How much space you want to give up for the enclosure...some subwoofers work well in big enclosures some in small...and some in between. SQ or SPL...or maybe a little bit of both for daily listening. Some subwoofers are made strictly for SQ...some for SPL...some are pretty versatile. Power requirements...

Exactly, all of the elements you mentioned (and more) are considerations you take when selecting a subwoofer that will sound great for a particular application. Are there any well thought out articles that outline in general which speakers perform best in those classes? What about a popular opinion for each subwoofer in each general class like this: Obviously this is all subjective opinion, but i think that a common popular theme would appear for each application.