Copyright and patents: 10-20 years maximum, depending on the industry. Trademarks should be forever, because that kinda defeats the point of a trademark if it expires.
Let me give an example I understand personally: Rubik's cubes. Rubik's cubes were invented by Ernő Rubik, and gained widespread popularity in the early 80s. In 1982 there was a speed solving competition, where Minh Thai got the world record fastest solve at 22.95 seconds. After this, the "craze" died out and it lost much popularity. Ideal Toy Corp sold the puzzle and retained a patent on it until 2000, after which was the second cubing craze. Sales doubled between 2001 and 2003, and the speed solving competitions came back. This time, however, solvers were not buying the stiff, clunky, catchy, sandy "Rubik's Cubes", they were at first appearing to be buying Chinese "knock-offs", brands which quickly developed recognition and brand loyalty among speed solvers. They were designed for speed, they had looser springs, less plastic, but "torpedoes" to keep them in place under other pieces, and cut out corners to allow imprecise movement. You can buy a better cube than the Rubik's Cube for less money than a Rubik's Cube. You can buy 10 speed cubes for the price of one Rubik's Brand speed cube, their failed attempt at capitalizing on the market. Rubik's Brand has spent the entire time up until very recently not interacting with the rest of the community, trying to sue companies out of selling their products.