I would choose the one that cost the least because it would not cost as much as the others.

Which one costs the least is the one to buy and use. Anyone of those will do what you want so the only consideration is cost.

I guess its as simple as that.

But I was hoping for, "I would chose the hemlock as it lasts much longer and doesn't compact like shredded hardwood", or "I would chose the bark mulch as it delivers more nutrients quicker".

Maybe its all subjective.

I actually have a new criteria...

Is there a type of mulch that is not as susceptiable to various types of fungus?

I got stinkhorns and slime mold this year...plus a white powder that I have yet to identify.

Various types of fungi help with the digestion of woody mulches and are, not only a normal part of mulching with woody material, but an essential part of doing that. A whiteish appearing powder under a woody mulch is probably the mycelia of the fungi that are digesting that woody mulch. The appearance of the various types of mushrooms that often appear in woody mulches is normal and tells you that the various fungi you have working in that mulch are happy and want to reproduce. The easiest method of "getting rid" of these mushrooms is something like a 9 iron used to drive them somewhere.