What can I write about the character I liked the most in the novel Twenty Thousand Leagues under the Sea?

The first thing you need to do to write about the character you liked most in Twenty Thousand Leagues under the Sea by Jules Verne is to read through the book carefully and decide which character you like. You do not need to restrict yourself to major characters, as you might find yourself sympathizing most with a minor character.

One example of the contrast among the characters is the following dialogue:

Conseil: If that is the case, this dugong may well be the last of its race, and perhaps it would be better to spare it, in the interest of science.

Ned Land: Perhaps it will be better to hunt it, in the interest of the kitchen.

As you think about choosing a character, you might ask yourself whether you support the scientific conservationism of Conseil or the pragmatism of Land. 

Next, you should give a basic description of who the character is and the role of the character in the plot. Such a description would include age, gender, nationality, profession, and what we know of the character's past history. Next, you should focus on why you like the character. For example, you might admire the drive and philanthropy of Nemo, the scientific curiosity of Aronnax or identify more with Conseil, with his flexibility and loyalty.

You should support your discussion with quotations which exemplify the characteristics you most admire of the character you have chosen.