"Tai Ji Quan" (Supreme Ultimate Fist) is probably the most popular Chinese martial arts style and is practiced by men and women all over the world. Taiji is actually a wushu style, just like Nanquan, Monkey Style, or Broadsword—only that Taiji is a soft, internal style. Nanquan, on the other hand, is an external and hard style.
Taiji is so popular because it even attracts people who are generally not interested in martial arts. For most people, its health benefits are more important than its combat aspect. However, there are also Taiji competitions that include acrobatic jumps and more. Taiji is definitely fun, improves fitness and coordination, and can be practiced anywhere.
There are many different Taiji styles: Chen (the original style), Wu, Yang, etc. In modern Taiji competitions, Chen, Wu, Yang, and acrobatic elements are often combined.