[Mezza]

ActiVillian on the SEA Bnet forums posted this on the bnet forums and as far as I know, its entirely his work, so I'll post the link here instead of plagiarizing it. Well there could be tons of sources for this but as far as I know, he's the dude who took the effort to compile it all in one thread, so here it is.

http://sea.battle.net/sc2/en/forum/topic/48665273

So if you're wondering which upgrade gets you more bang for the buck, this thread is here to answer your question.

Like for example: TvZ
marine vs zergling, upgrading +1 armor keeps your marine army alive longer than with +combat shields

Was looking around for this to refresh my own memory and thought it might benefit some of you guys as well.