I don't know if David Clarks are "generally the best", but certainly you will see that more pilots own them than any other brand, which I suppose says something. In general, they are robust, medium-priced, and comfortable for most people (not all; try before you buy).
Personally I like the DC-13.4. I have owned one set for about three years, and last year I bought another for my wife. No problems with either set, and we have both worn them for +5hr flights.
I respect Circuit Basher's opinion, but disagree with the advice that you should buy a cheap headset with the idea of upgrading at some later date. There are few things that will detract from the pleasure of flying more than a headset with poor avionics or a poor fit. This is equally true for passengers, so the idea of passing on the cheap set to your significant other or whomever doesn't make sense to me.
I doubt that you will really know more about your headset preferences after you have X hours flying experience under your belt, so my advice would be to conduct your research now and but the best headset that you can afford. Don't be afraid to borrow or rent different types to that you can actually try them in the airplane for at least 1/2 an hour.