Mecha Anime is one of the biggest shounen genres out on the market. It is usually about a teenage boy who has to save the world by controlling a giant robot. Examples of this genres are found in largely producted shows such as Code Geass Lelouch of the Rebellion, The entire Gundam series, Macross, and Neon Genesis Evangelion. Most of these shows are so influenced that some companies, such as Bandai, have even created small die cast and plastic figures of the giant mecha that are seen in the anime.
There are also some Shojo shows that are Mecha. One of the most known and highly emphasized is the show Eureka Seven. The shoe could be classified as a shounen anime, but many of the episode focus on how the main female character reacts to her world around her. Because of her eactions droves the rvolution of the entire story arc forwards.
In the fanime community though there aren't that many people who have actually started a mecha fanime because of the difficult to make the robotics move in a flowwng manner. But one notable mecha fanime, though with few mecha parts to show is 'Gekisen' by MewSakuraKikkipurin.