One of the things that always worried me in the past is the stability of stacked cakes. Unless I was using those steel support rings (forgot what the actual name is), I always worried that what I was using was not enough.
I have used the bubble tea straws (the only thing I don't like about these is the large holes they leave for some of your cake slices), wooden dowels (which I wonder if they are just too thin), regular straws and pillars.

The steel support rings are expensive and I don't like using them on cakes that I am afraid I will not get back again or pieces will get lost. I use them only for weddings where I charge a deposit for.

So my question is, on your everyday stacked cakes, is there a fool proof, rock solid support to use to take away my fear of the cakes sliding or falling??

Have you tried SPS? There is a sticky at the top of this forum about this system. It's about as full-proof as it gets and it is inexpensive.

I really like the SPS.

http://cakecentral.com/cake-decorating-ftopict-603925.html