Choosing the right type of speaker.
Will you have the floor space for stand alone speakers, or would you prefer the built-in look of ceiling or wall flush mount units? Consider how your TV will be installed. If it will be attached to the wall, or builtin to a cubby-hole, then floor speakers are probably not the choice for you. Wall or ceiling mounted would be the better choice.
Floor Speakers / Tower Speakers
The are the best sounding speakers available. They often have multiple midrange drivers and tweeters to display more accurate and precise audio. The woofers that are built into the towers develop bass frequencies more accurately, so it may be unneccessary to invest in a subwoofer.  They are also designed to handle more power without distorting, so a good amplifier or reciever is a worthwhile investment.  Soundwaves can find the best amplifier match to your speakers.  Towers and floor speakers are mainly used in home theatre settings and high end stereo settings.

Bookshelf and Satellite Speakers
Bookshelf speakers provide quality sound in non-home theatre situations The are very pratical in living areas where space is a neccessity, because they tend to be compact.  They are fairly good at reproducing bass sounds and usually have good tweeters for high frequency reproduction.

Flush-Mount Ceiling
With flush-mounted/ceiling speakers the appearance goes away into ceiling or wall.  These are more aesthetically pleasing and tend to provide more than acceptable music reproduction.  Typically these are used when a whole house audio situation is desired.

Outdoor Speakers
Outdoor speakers provide quality sound on deck & pool areas.  These are designed to withstand harsh weather conditions, typically found on the Outer Banks.

While it is possible to get along for some time without the aid of a subwoofer.  When you do add one, you will wonder why you didn’t invest in a subwoofer in the first place.  It’s just not possible to experience a real home theater without a good sub woofer.  Subwoofers provide the exciting and heart pounding thump that you FEEL when T-Rex is coming from behind, or Maverick’s F-15 is zooming by.  Most speakers are simply not capable of the subsonic audio reproduction which is why it is necessary to a proper home theater experience.