Please take note that Histrical Romance was not included in this list as it will have a list of it's own :)

Disclaimer: Details were taken from http://en.wikipedia.org/wiki/Romance_novel#Subgenres

Contemporary Romance - It is usually set after World War II. It is also usually set in the time in which they were written. It is the most common genre of romance novels.

Romantic Suspense - The story usually involves an intrigue or mystery for the main characters to solve. Generally, the heroine is a victim of a crime - whether successful or not - and the hero would serve either as a protector, police, bodyguard, etc. At the end, the mystery is solved and the two fall in love in the process.

Paranormal Romance - It usually involves fantasy or science fiction. Characters may include vampires, demons, werewolves, witches/wizards, fairies, psychics, etc. 

Time-Travel Romance - It is commonly about the heroine traveling to the past to meet the hero or the hero traveling to the future to meet the heroine.

Inspirational Romance - The story incorporates Christian values and themes

Multicultural Romance - The hero/heroine is usually is a descendant of two races; example of which is African-American, Asian-American, etc. It also includes relationships

Romance - It is characterized by strong ual content and it may contain elements of other genres of romance. It should NOT be confused with ography as romance includes well-developed characters and can stand with or without the scenes.