According to my experience, Tai Ji Chuan has a high demand for leg strength, and his knees can't stand it after practicing for a while.
Wuqinxi is the most interesting and simple one for me to practice. I feel good after practice.
Baduanjin is also relatively simple, similar to Wuqinxi. The combination of action and breathing is easier to complete the exercise, and Wuqinxi is more interesting.
Yijinjing pays more attention to ideas, combining breathing with movements, using ideas to promote qi, emphasizing the unity of form and spirit and the harmony of yin and yang. It is effective to treat diseases, but some movements of Yijinjing are difficult and need to be learned slowly. Moreover, the Yijinjing is not taught by the master, and it is easy to get possessed by yourself, not alarmist.