This thread is hysterical...I don't think you can have a reasonable discussion like this without defining what you mean by rich, middle class or lower class, etc.
So here's some ideas:
Range 1 - Upto $60k/yr
Range 2 - From $60k - $100k/year
Range 3 - From $100k - $300k/year
Range 4 - From $300k - $1mm / year
Range 5 - More than $1mm -> lucky bastards
Some people may think they are middle class but to you they may be super filthy rich, etc.
Nowadays, what used to be considered rich or wealthy a few years ago is now middle class!
I'm towards upper Range 3, just turned 28 and the iPhone was pretty much an impulse buy which I got hell for from my wife

Don't drive a fancy car or anything like that but I love me some gadgets...my one weakness!
BTW, to the previous poster who said he was lower middle class but has a '07 BMW - not sure how having a 30k+ car (at a minimum) can be considered to be lower middle class, if anything you're probably middle to upper.