Value for money is my mantra.
If I can get 70% of the performance of the high end solutions at 30% of the price, that's what I want. I'm not a gamer, so the other 30% of extra performance don't matter to me. Not being a gamer means I can almost disregard the video card.
An easily and highly overclockable CPU would interest me. I'd not go crazy with it, try to beat records, put advanced cooling systems in place etc., but I want to go for an extra performance boost at minimum cost and risk.
The motherboard is also pretty important in my book. It has to get good reviews if I'm to trust it. The hard disk and internal memory come next. I care about them, but I'm not ready to pay a lot for them. I can sacrifice some disk space size for speed though.
All that is for desktops. I don't care for laptops yet.
Just my way of viewing things.