The best part of The BFG is by far the incredible CGI effects. Team Spielberg truly out did themselves with this one, with amazing set pieces and designs, especially everything centered around the dream world. Another highlight of the film is Mark Rylance as the Big Friendly Giant; there's no mistake that the two go extremely well together. However, by the end of the film you can't help but wonder what it would have been like if someone other then Spielberg would have directed the acclaimed child's tale. However, he did do it, and more importantly, Spielberg did to an overall satisfying job on the film.
The thing about any Roald Dahl novel is that they can be open to so many different interpretations. Spielberg decided to go the very P-G and kid friendly route with his big screen adaption, and there's almost nothing wrong with that.
However, there were some very darker parts of the tale that would have done wonderful in the hands of other well known fantasy directors, like David Yates or everyone's favorite Del Toro. Whether or not Spielberg himself was the right choice for this movie is open to suggestion, but for now we can say that even with the family version, he did a great job.
Everything in the film looks wonderful to look at it from beginning to end, and especially when they go to Dream Country, your amazed at everything on the screen. The way they enhanced the Big Friendly Giant, and the other Giants is incredible. They look exactly like you'd imagine them to look like from the novel, and the little girl that plays Sophie fits the part well.
The thing that Steven Spielberg nailed is the dialogue which is almost directly from the novel. By the middle part of the film you'll be laughing and chuckling along with The BFG and Sophie's wonderful adventure, especially when they visit the Queen of England.
Despite it being extremely family-orientated, The BFG is very successful, and adapts the best parts of Roald Dahl's novels onto the big screen. Most fans of the book won't be disappointed.