I cycle through all the 4 - 5 star grainless kibble, and the different flavors in each brand.
I will say that at least for my two, the fish based ones tend to give them a more...er...fragrant?
poop than the others. Of course, ymmv so don't let that stop you, at least till you try them all out.
It's particularly noticeable with mine just because for the most part, their poop has very little odor....a lovely side effect of feeding them a superior quality food.