In my opinion, the best gift is money since the person you're gifting is more likely to know what they want than you, or they could wait for a good sale or something. If not, I would say a new or second graphics card is a good gift.
I have a fairly standard setup. I run a 120 GB Sandisk Extreme SSD for boot and applications and a 1 TB WD Caviar Blue for music and games. I chose this because of the reputation and reliability of these 2 drives as well as the speed of a relatively cheap SSD.