Yeah, super plotholes. Though I like the cell saga probably because SSJ2 Gohan for the first time was pretty cool, and almost every fighter is useful at some point, even if just for a little. The time travelling crap is also a downer though, I mean Dr Gero basically wins the whole series since he got his revenge Goku's friends and family, even if it was an alternate timeline. A crappy villain from DB ends up wiping out the entire cast in the future......lame.
Namek saga is probably the best story-wise, since Frieza REALLY makes you hate him, and is definitely the most ruthless villain, and watching Goku go SSJ for the first time is a memorable moment. (Though he didn't beat on Frieza enough IMO)
Saiyan Saga is good because Goku vs Vegeta was classic, and it lays the story out extremely well for future sagas. Also the fights are a bit more substance based than light shows, and the saga isn't as longwinded (Frieza saga got really tedious at times, with Namek looking exactly the same)
Lastly, Buu saga was ok, so many power ups and fusions, but it lacked a serious plot. Buu changed like 50 times and instead of killing people (besides fodder earthlings) he turned them into candy, and there were way too many comical moments in the middle of fights (Gotenks was freaking annoying and obnoxious)