Metaphysical.
The TV was not invented until the 20th century! TV actually evolved over a period of time, but didn't really get going until well into the 20th century...so does your query refer to the most popular TV show of the 20th century (1900s, i.e. 1900-1999) or the most popular make of television during the same period ?
impressionism was popular in 180 B.C. the most popular impressionists are Vincent Vangough leonardo davinchi and leonardo dicaprio
John, William, James, and George were the most popular baby names in the 19th century.
The name Lisa became popular in the United States during the mid-20th century, particularly in the 1960s and 1970s. It was one of the most popular names for baby girls in the U.S. during that time.
In the late 18th century!
Shopping
Programme music was most popular in the 19th century.
Congress was the dominant political institution in the US during most of the 19th century. The presidency became more powerful during the 20th century.
baseball
Feudalism started in the 9th century, during the Medieval Era. It was very popular, but most nations now are not using a feudal system.
Triangular composition was most popular during the Renaissance.
LEGO !!!