Honestly I do love all three! But especially Dragon Ball and Dragon Ball Z..there was just something about the two besides me always watching the two when I was younger! but there just something about Dragon Ball Z that I loved and enjoyed watching!

Dragonball:
was a good comedy series to begin with(toriyama started it as a comedy until near the end of DB)
had a decent enough plot to read through without many breaks.

Dragonball Z:
fights were ok to good
amount of plotholes and lack of plot at times(Toriyama apologized for this)
I had many breaks reading it and dropped it just before Super Buu appeared.

Dragonball GT:
fights were bad to ok
terrible plot, stated by many hardcore fans surpringly
Non-canon
made of plotholes
haven't re-watched it since it stopped airing in the UK years back.

dbz is the aossme