It's really been 15 years.
The franchise has certainly had quite a complicated history on UK TV. Basically it went as follows:
-Saban Ocean dub for episodes 1-53
-Funimation inhouse dub for episodes 54-107 (and for the Fusion saga during its first few runs on CNX)
-Westwood Ocean dub for the rest of Z
-Blue Water dub for GT and the original Dragonball
-Big Green dub for the Movies and Specials
-Funimation dub for Kai
I remember watching bits and pieces of the Saiyan and Namek sagas on Cartoon Network UK and liking what I saw. Then when the fight with Frieza aired I distinctly remember seeing Vegeta's death scene and getting completely hooked on the series. Goku vs Frieza still remains my favourite fight of the series to this day. I remember not being able to wait to get home from school to see if Goku would complete the Spirit Bomb, and then seeing the preview for Transformed at Last and getting even more hyped. I then continued watching until the episode were Trunks warns Goku about the Androids only for it to go back to Raditz. They would repeat the Saiyan-Trunks sagas for what felt like the longest time until the Android saga finally aired in early 2001.
I have really happy memories of watching daylong marathons of the Saiyan and Frieza sagas many times. For some reason whenever they restarted the series they would air the first couple of episodes during school time, so I would always miss the Arrival of Raditz and would come home when Goku and Piccolo were already fighting him, or sometimes after the fight was already over.
When the Android saga finally did air, although I didn't like the switch to Westwood dub I was happy to finally see new episodes. It continued on Cartoon Network UK until the end of the Fat Buu saga. Then after a long wait, in October 2002 CNX started and we got the rest of Z. I remember them showing promos for GT before we'd even finished the Kid Buu fight, and then GT immediately airing on a Monday after Z ended on the previous Friday. Outside of Kid Goku, Trunks and Pan, and a few villains, I really didn't like the Blue Water dub of GT.
Eventually CNX turned into Toonami and then we got the original Dragonball around September 2003. I actually found the Blue Water dub of DB to be much better than their GT dub. The entire series aired in just over a year but was only shown in full a couple of times unfortunately.
2005 was truly the beginning of the end for Toonami UK. DB and GT got taken off, and for some strange reason they would only air the first half of the Imperfect Cell saga for Z and then start that saga again over and over again. I remember during the May half term when the Big Green movies aired and they promised to show the greatest episodes of Z along with them, only for them to air half of the Imperfect Cell saga and then restart it(again). In the end it almost felt like they were trying to kill the show off, as crazy as that sounds.
But on the whole DBZ still made my childhood a great one that I still look back on fondly.
Then you had to grow up. 
This was after the Cell Arc finished, and months later I was bored flicking through channels and found CNX, airing DBZ, I believe it was the bit where Buu turned Vegetto into candy that was like the second happiest day of the life! (first being watching ep 1 of DBZ of course!) I believe CNX also aired GT too I didn't like it at all and never bothered with it lol 
Brilliant stuff DBZimran, it's great to see all these old ads again.