Aoyama is best known for his Detective Conan (Case Closed) manga series, which has spawned a television anime that has been running since 1996, as well as an accompany anime film series. The 21st film in the series, Meitantei Conan Kara Kurenai no Love Letter (Detective Conan: Crimson Love Letter), opened last Saturday with the highest opening weekend record for the franchise.
Aoyama also drew the Yaiba and Magic Kaito manga. The latter has spawned a 12-episode television anime special between 2010 and 2012, as well as a 24-episode television anime series titled Magic Kaito 1412 in 2014. The main character of Magic Kaito makes occasional cameo appearances in Detective Conan stories as well.
Update: Magazine title corrected. Thanks, Jano07 and Shinuki