Granted, I have only read about the 3 stories: The Time Machine, The Iceland of Dr. Moreau and The Invisible Man.
Each of the three books deals with scientific experiments that are really logically explained and understandable. These form the backbone of each of the stories and are very varied.
Besides the books, however, are also very critical of society. This is particularly striking in The Time Machine, showing how the world changes over time due to the action of the people.
The characters of the three stories are well drawn, appear realistic and make a comprehensible transformation through.
My current favorite is The Time Machine, as it is the most exciting and emotional work. The modern film starring Guy Pearce is nothing compared to the original! The other two stories are also very good, but also have their lengths.
On the content, I will not go into detail, as these are self-explanatory based on the title and you should let yourself be surprised.
Attention: The Time Machine is a "shortened" version, in the eleventh chapter is missing. This Wells has written but only at the proposal of lector and even taken out of the book.
Ultimately must still something to be said for the language. The plants are older and have accordingly an obsolete language. Those who do not read a lot of English, will initially be here very overwhelmed, because much of the vocabulary no longer, or at least rarely used today. I myself had at The Time Machine often look in a dictionary and have still not understood each sentence, but you get used to the language and the essence is quite understandable.