Meh, if you ask me there is plenty of "other stuff between fights" even into the Buu Saga... all be it does get less important.
We of course have all of the traveling in the Raditz conflict (which naturally Sagas and Legacy of Goku tried and failed to expand appropriately... though I'd say LoG had ... decent... ideas there?), of course all of the training business for the Saiyans, Goku in the afterlife, all of that training... and of course more training. T.T. Namek was actually slow on the fighting until the Ginyu Force showed up, and was more about strategy (A DBZ strategy game?

!). Even during the Freeza fight, at least until Goku showed up, it was more strategy than all out combat, because... well... that was the only way to not die (and that worked wonderfully... o_o).
Lezee, Garlic JR had plenty of that... for Kami and Popo. >.<. The Cold business... I could see that working out in a sagas-esque way, actually.
Training. Woohoo.
And again in the Jinzouningen and Imperfect Cell arc(s), everyone knows they only have a couple aces and a lot of strategy and moving around and not fighting are involved.
Then of course we know the fighting between Cell and Buu was limited, so something completely crazy could spin out of that (and could turn out awesome, but probably wouldn't sell well unless it really played the characters in a fan-pleasing way).
Buu's Fury didn't do too bad at expanding on the Buu Saga stuff, but even without the "filler" missions and the movie references, we have the usual DB quest and more strategy, all be it less adventurous; heck, it'd probably be more exciting to play as Mr. Satan in the Buu saga...!
And GT... is written like a video game. :O.
And of course if we make a game that starts with DB, problem solved. ^^. But clearly the marketability of something Dragon Ball sans Z in North America is less likely to be undertaken.

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