If you were building a computer what components would you use, and what would you keep away from?

I'm asking because I'm thinking about getting a new computer built specification, and i was wondering what components you would recommend using.

Type of Mother board processor and spec?
Type of Ram and spec?
Type of Hard drive and spec?
Type of Graphics card and spec?
Type of Sound card and spec?
Type of Dvd drive and spec?
Type of CD Burner spec?

And any extra components you think would be useful.

Thanks for your help

Adam