Componets you must have for your desktop build?

What components do you find necessary when building your desktop? I think it has been years since I have included a floppy drive in a computer. CD-ROM/DVD depends on what I am doing with it. I have a bunch of extra cd-roms around so I can usually throw one in, but I don't really feel a DVD-Burner/CD Burner is essential. Especially since I have an external one I can just plugged in as necessary.

I guess my key components would be:

motherboard (obviously) (usually onboard sound, network card all that so I don't have to mess with the extra cards)
cpu (obviously)
memory (obviously)
USB 2.0 ports. The more the merrier
cooling case
extra fans


That is really the core for me. Keyboard and mice are just pulled from the junk pile.