A book like this, especially with the words 'ultimate encyclopaedia' in the title is leaving itself wide open to fairly harsh criticism. This may be deserving or unfair depending on your feelings. It also largely depends on what you paid for it, I guess. The book has no visible RRP, but I am guessing it was not cheap. I picked my copy up at a bargain price, which is why I am happy to sing its praises.
To be fair, a book like this is going to be out of date before it hits the bookshelves.

Aesthetically speaking however, this book looks very slick, with just the right balance struck between illustrations and text. Flicking through the pages the editors choice of featured illustrations hit just the right chord with this fan and even includes some rare personal favourite that I thought no one else would remember!
I am sure there are other superior examples of this type of tome, but I am certainly going to enjoy several hundred hours of nostalgia.

A great coffee table book! ( )

I have two 'Illustrated Encyclopedias of Science Fiction' and this one is definitely the lesser of the two.

It contains a reasonably comprehensive alphabetical list of authors and chronological lists of television shows and movies.

The book starts with a discussion of various genres of science fiction and provides examples of how these genres have evolved across the decades.

The final chapter is an A-Z of villains and heroes, which must have been fun to compile, but isn't particularly helpful as a reference tool. It takes up space in the encyclopedia that could have been dedicated to other things (perhaps a list of hugo and nebula award winners as suggested by another reviewer).

Having said that - the text is only part of the value of an illustrated reference book. The pictures of first-edition covers alone make this worthwhile for lovers of science fiction books. ( )

Not so very definitive - doesn't even include lists of Hugo or Nebula winners. ( )