For me the answer is easily the Boo arc. The most obnoxious, random ass pulls came from there. I find it humorous they took everything I despised from the Cell saga and multiplied it by 5. Toriyama is one of those writers I can chuckle at and look past when he does silly things like using the magic water shtick twice or when he makes some clusterfuck of a timeline. He's Toriyama, he has little regard for the petty spergy complaints of neckbearded 40 year olds. I can respect that. When you have shit like two 8 year olds that can literally go Super Saiyan on the fly for absolutely no explained reason, Super Saiyan 3 which I believe is the dictionary definition of an ass pull, a conveniently learned fusion technique that happens to have the exact requirements for the situation you had just gotten into, ANOTHER form of that technique that you’ve happened to stumble upon by chance that uses magical enchanted earrings, having that very technique and all the build up to it be all for naught thanks to “stale air” whatever that means, jerking us around about who’s going to be the hero (Gotenks,Gohan,Vegetto...oh it’s Goku again huh?) and Oob...just Oob. When you have all of that and much more in ONE saga it stops being petty stupid complaints and starts being you not being able to tell a competent story. Shit was getting goofy during the Cell arc and that’s where I hit my “letting shit slide” peak personally but it never went over.
I’m not saying Toriyama is a bad writer for the record. I’m going to quote Charlie Sweatpants of
http://deadhomersociety.wordpress.com/ for this
“these kinds of criticisms apply to pretty much any franchise that lingers around too long, whether it’s books, movies, or television shows. At some point, almost everything decomposes into fan service at the lowest common denominator, and once that happens everything else (story, character development, things making any sense at all) becomes an afterthought.”
which is simply why I just want Dragonball as a whole to end.