If you're a proficient player of Dungeons & Dragons, you'll want to get the Player's Handbook (3rd Edition) instead of this set. But if you're either (a) curious about role-playing, and have never tried it, or (b) eager to introduce your friends to your favorite hobby, this set is an absolute must-buy.
Why? There are several reasons. The first is the value. For one low price, you get a rulebook, 48 pages of unique adventures (all high quality and very playable), dice, 2 sheets of gorgeous full-color counters, a giant poster map, 8 pre-designed characters, and a set of quick-start rules that will have you ready to play in 30 minutes. And when you consider that there's enough material for the Dungeon Master (storyteller) to write his or her own adventures, you have a starter set that will keep you busy for at least a hundred hours of play. Compare that to the price of a movie!
Second is the graphics. The illustrations are stunning, evocative, and flat-out beautiful; not only do they give you a vivid idea of who populates this finest of all fantasy worlds, they also make you want to become a part of it. Wizards of the Coast have truly outdone themselves here.
Third is the "bridge factor." You will indeed need the Player's Handbook later on, but there's no better way to "ramp up" to that work than this set. You'll go from absolute novice to enthusiastic veteran in a matter of a few months, and it will all be because of this box.
Fourth is the production qualities. The books are very well-written, the adventures are cinematic and entertaining, the instructions are clear, and everything is explained cleanly and logically, with a minimum of confusion. (Anyone who remembers the "red dragon, blue book" basic set from the 70s will be pleasantly surprised. ;)
So... Is there anything wrong here? Yes. Rules are only provided for 1st and 2nd level characters. With an enthusiastic group, you might be able to plow through that much gameplay in just a couple weekends. There is enough play value here for many more game sessions; but with the "2nd level wall," you'll have to keep creating 1st-level characters if you don't buy the Player's Handbook. But this is a minor quibble; the Basic Set has always been intended as a starter product, leading to bigger and better things. And considering the replay value of the maps, counters, and dice, every veteran player should snag a copy of this as well. It's that good!