My .02:
If the car is supposed to take premium - I give it premium and nothing else. If the manual, etc. states that 87 octane is suffice - that's what I give it (i.e. my Accord & 4Runner).

As previously stated, premium is not that horribly much more than regular when you consider the peace of mind (al least IMO).
My 97 Prelude required premium so that's all I put in it. Had it for 9 years and no issues whatsoever.
My father-in-law HATES paying for premium fuel. He had a Park Avenue Ultra (SC 3.8) a couple of years ago that was supposed to take premium - but he used 87. This resulted in constant engine 'pinging,' decreased performance, and other issues.

He now has a Acura RL and a Corvette - and I try my best to make sure he puts premium in those.