King of Wands - Forceful, domineering, risk taker, creative, sets high goals
King of Cups - Romantic, charming, fun, sensitive
King of Swords - Analytical, intellectual, ruthless,
King of Pentacles - Down to earth. sensual, secure, stubborn

Kings IMO are similar to Queens in that they represent someone with power over the querent. They are different in that they manifest the characteristics of their suits in a stronger, more raw manner. They can be excessive, or heavy handed where the Queen is usually more balanced and reserved.

Richard Gorden in "Intuitive Tarot" states that "Kings represent a great deal of awareness, combined with an assertive nature, or an adult man."

Sharman-Burke and Green in "The Mythic Tarot" writes "Kings in all four suits are images of the dynamic, outgoing, directive qualities of the particular suit. These powerful masculine figures represent the full use of the energies of this sphere of life in building and concretizing in the outer world."

Mary Greer in "Tarot Constellations says" "...(court cards) primarily represent the roles, masks or subpersonalities we wear as our "identities" in life....The kings demonstrate their talents, which are outer and public.
They seem confident of their expertise and secure in their positions. As a king you administer, judge, take charge and handle your affairs competently. You establish procedures and build empires.
Kings show where you have developed mastery, but also where you can be inflexible, and where you think you have nothing more to learn. Kings are much like the Emperor. They are usually related to the element air, but may be considered fire by some." I personally consider them fire.