When i build my 90G, i intend to have the following fish contained within it. Please note, i don't really have much experience, but i have thought this out over the course of 2+ years and i've definitely done the research.
Once acclimated, i'll add 2 false percs (hard to argue with these fish... IMO if you don't have 2 of them, you're been in this hobby long enough to be bored with them. i'm nowhere near that).
In another month or so, i'll likely add 3-5 green chromis. Whether i add 3 or 5 depends on how the system is holidng up. I woudl consider adding 3 cardinals at this point instead, but they're pretty expensive relative to the price of some chromis so...
Next i'll probably add a yellow watchman goby. They're cool. Why not?
After taht i'm probably going to introduce my first tang into the picture. The system shoudl have enough action at this point to make a tang feel at home. I'm leaning towards a hippo (which i would prefer) but i'm trying to find the hartiests, prettiest, most 90G compatible tang to add at this point. I want to be as responsible as possible with the tang i chose as my centerpiece. I know a 90G is considered borderline for a hippo, but i know a few people that have had long term (8 yrs +) success with hippos in a 90. More research needed to say the least although i think i've read it all at this point.
after the tang addition, i'm going to add a dragonette of some sort when (and only when) massive copepod levels seem to have developed.
The final fish i'll add will be a six line wrasse.
At that point i'll acess my system. If it's holding up well, i will consider adding two more small fish. But i'll likely stop there.
Pepper in coral additions throughout as well as cleaner crew maintinence and the addition of a few cleaner shrimp (added prior to the tang), some emerald crabs and a detritus consuming starfish and that's what i'm going to have.
It's really a standard stocking package. Nothing special. Nothing exotic. But i think it's a responsible plan. It may be a tad towards the heavy fish loading end, but (again) i'm not going to add a damn thing if my parameters seem to indicate that it would be a bad idea.