Paul's got that right. Listen before you buy.
Paul, love those RS-2000's. I've got a pair of RS 2001's a friend gave to me about 10 years ago. The 2001 is a slightly larger, with a 6.5" rather than 5.25" woofer, version of the 2000. I use a home-built single-ended valve amp that seems to soften some of the harshness. Most of my friends hate (no, that's not too strong of a choise of words) those speakers because of their lack of bass. Yet another case where you should listen before buying.
VMPS, wow haven't heard that name in years. A friend used to have a pair of their 7 foot tall(!) speakers. He bought it as a kit from VMPS, and I helped him finish and assemble it. True 20 Hz bass is very impressive. The midrange on those were almost as good as with my 60" ribbons that I bought from a friend who had a pair of Genesis 1's ruined by a mover. If the bass on their subs is anything like what I heard from one of their towers, it's a definite good choise.
It's strange how almost every time the topic of a sub for home comes-up, someone mentions Velodyne. They must be good. I need to find one to listen to sometime.
Zippy, Klipsch, that Paul mentioned, is a good choise for bass. While generally speaking, I don't like their speakers, I really like them for rock music. I would imagine their subs would be perfect for rock or movies. They're very dynamic, for lack of a better word.z