DRAGONBALL GT
well this is all i got on dbgt.
its not much but it will give you at least a little outlook of the story.
well i know the first 3 sagas but i only know the names they are:

-Bebi saga
-super android 17  saga
-Evil Shenlong saga

thats all i know for now
OK here's some info on the Bebi saga.

Well to start off you should all know who bebi is becuase they talked abotu him in DBZ. Now bebi is the Japan way for saying bibby bobbys father.  He comes back to earth to terroise.
(more to come on this)
i will have a lot more soon!
OK i know a lot on the super android 17 saga. 

I dont know how it started but android 17 IS still alive.  He creates a cyborg Dr.Gero.  Then the cyborg Gero creates the normal Dr.Gero (the one you saw in the androids saga back in DBZ.) Then they work togeather to build another Android 17. So when thats done they start terroising people.  Intill they here valubal information.  They overhear trunks and goten talking about fusion.  So the androids get an idea.  They will try it.  they tried it 3 times and bad enough they got it.  So when they fuse togeather they formed Super 17 witch cause a whole mess.

(more to come)
I have a movie whitch shows both 17s fusing (has sub titles)

here it is

Super 17 movie
(sry if it doesent work im still trying to figure it out)