I have been recently looking into many Dragon Ball fan series and I would like to recommend some if you are the type of person to go for more DB.
(almost everyone knows about this one)
This is an amazing series done by youtube user and animator, Melavelli. There are only 2 episodes and a few shorts, but this one is AMAZING. So please support and subscribe to his channel if you want more of DBA.http://www.youtube.com/channel/UCFumqlOOt7nv4h_FGyZYF6Q
This is a Spanish manga (read from left to right instead) that happens after GT and is about an evil version of Goku who attacks Earth. Link to original:http://www.sebliet.com/ Translation:http://www.sebliet.com/2009/02/dragon-ball-ex-english.html
Amazing manga series done by artist, MALIK. It also happens after GT and starts with the arrival of Vegeta's immensely powerful half-brother who attacks Vegeta and Earth. Link:http://krazykat001.deviantart.com/favourites/47897557?offset=360
(note: the link that I posted starts at the last deviantart page, the first deviantart page is where the latest chapters are)