Picking up where Dragonball Z left off, Dragonball GT is considered by many as a poor final chapter to the Dragonball franchise. In some cases, they are right, as this is the only series not based off of Toriyama's manga and said manga-ka also had little to do with the series. However, judging it solely on that is unfair, so I'll try to do my best at giving GT a proper review.
The one major thing that Dragonball GT suffers from is an identity crisis. It starts off as a primarily comedy anime with action as a secondary, something that worked very well for Dragonball and occasionally worked here as well. Unfortunately, the series received poor ratings, mainly because everyone wanted more action and less goofing off. At about Episode 17, the focus shifted from comedy to action, and that's also when the plot started to suffer. It's difficult to be original when one uses plot devices that have been seen in so many other anime, not to mention done better. And as well all know, with a lack of originality comes boredom. At least this series is "only" 64 episodes in length, so it's not as much of a chore to sit through as, say, Dragonball Z.
On an more positive note, the art and animation received a nice upgrade. Some of the character designs are a bit iffy, but it's still passable. The music is also rather good, especially the opening, DAN DAN Kokoro Hikareteku, and all four endings. I can safely say that I enjoy listening to all five songs on a regular basis. The fights are enjoyable more often than not, though once again, I've seen better...much better.
It may be far from perfect, but Dragonball GT at least makes an attempt to be entertaining. If you still want to watch, then by all means, go for it. Just don't expect too much, and enjoy the opening and endings as they come.