Welcome! "The Best" is really sort of different for everyone, but being new here myself I got opinions and recommendations from a lot of folks on these boards. You have definitely come to the right place! Look around, read lots of info, watch the videos, ask lots of questions.
Some of the more popular ones that are good quality and recommended over and over are listed above by cskent.
ANY of those choices are good for us beginners really. If it is important to look and feel sort of like a real cigarette than the Joye 510 is probably the closest or the KR808 which is a little longer I believe. If you don't care what it looks like so much, go with a eGo or Riva. Personally I settled on the Riva because it's basically a clone of the eGo and it's little cheaper.
Whatever you do, just don't rush into buying something, read, ask questions here and make an informed decision. A lot of us, myself included fell into using google to search for "E-Cigarette reviews", or "Best electronic cigarettes", or similar searches which mostly will leading you to some crap sites that tell you to buy over-priced stuff that is not so great. If you have not bought one yet, then you are doing well, as you made it to this forum before spending money on something you might not be satisfied with, like I did. It did get me started and got me away from smoking though.
There is a ton of info and it can be very overwhelming, just relax, post any questions you have, and things will work out fine.