For a highly refined system that is comprehensive, easy to learn, widely available and has a good fighting reputation Isshinryu karate is an excellent choice. Uechi Ryu karate. Wing Chun gung fu. These three also have some real interesting forms, If you are more into the art side of things. Jiu jutsu is real good for self defense
I would not recommend Tae Kwon Do, although they do get some cute girls.
If you don't have a lot of money look into a local after school karate class or your local Y. You can find some excellent instruction at such a school. These schools tend not to be diploma mills where you get lots of rank quick, unlike the local Mcdojo.
Other than using biomechanically simple techniques there no short cuts in martial arts.
Also it is best to start with a hard or Yang style like karate rather than a soft or Yin style like Tai Chi. Because it is easier later on to move from a yang style to a yin style than the other way around.
If you don't already have a background in an art to build upon it is extremely difficult to learn from books and tapes.