I dislike this idea of an "all-purpose build". Everything is based on scouting and assuming the opponent is going down one path. It's more like there's a best response strategy for everything the opponent is doing. That follows from the idea of hard counters being really emphasised in SC2.
Lack of scouting common among all races:
"Just in case" builds:
Emergency defenses
Concluding remarks:
EDIT: Sorry for the long read. I hope I at least sound sensible. Probably just incite a lot of Zerg hatred since I play Protoss.

Don't think my opinion/points are completely useless though.