Gustav Klimt was a leading figure in the movement of the turn of the 19th century called Art Noveau. This movement is characterized by plant inspired lines and highly stylized motifs. Klimt tends to portray female figures in warm colors and even gold leaf, such as in The Kiss. His work looks very busy, often containing many figures and patterns, but still maintains a balance. Although it is busy it is not cluttered. What I love about his work is how he tightly crams many figures and shapes into a space, but leaves negative space in the surrounding areas. This is how he achieves balance.
you can find out more about him and view more of his work here.