If you didn't know, Wiki will explain it best for you!
Weekly Shōnen Jump (週刊少年ジャンプ Shūkan Shōnen Janpu?) is a weekly shōnen manga anthology published in Japan by Shueisha under the Jump line of magazines. The first issue was released with a cover date of July 2, 1968, and it is still circulating. One of the longest-running manga magazines in Japan, it has a circulation of 2.8 million copies (2009). The chapters of series that run in Weekly Shōnen Jump are collected and published in tankōbon volumes under the "Jump Comics" imprint every two to three months. The manga series within the magazine target young male readers and tend to comprise of a large amount of action scenes and a fair amount of comedy.
Mine has to be Gintama and SKET Dance. Absolutely in love with these light hearted anime. Especially with Gintama's author, Sorachi, being a master of pressing the right buttons that just make you touched. It's awesome how one of his assistants branched of and created his own manga- Sket Dance. It is quite similar but bother have their own charm!
So what's yours?