I think the key to gift giving is that it should be from the heart.
Every so often I have difficulty picking a good gift for a loved one, but usually, if you know someone well enough that you buy them gifts, you should know them well enough to find something they like. I usually consider gift cards like politically correct language. Both cash and gift cards come from the same place in your heart, which is usually:
"I don't know you well enough or am too lazy to pick out a good gift."
But the gift card says it with glitter and penguins.
I also feel like a gift card is giving someone money and then chiding them to spend it in a specific manner. "Well, Bob, you can't be trusted to make your own spending decisions, so here's a financial training wheel."
Sometimes I do buy gift cards in special circumstances:
1. Money for people who really can't be trusted to spend it wisely: a Safeway gift card is slightly more likely to be used on groceries than something sketchy. Sure you can sell the card at a loss, or you can use the money you save on groceries for drugs- but at least it wasn't my money.
2. Cards to sporting events, restaurants, craft stores: Gives your recipient an understanding that you know what they like, but didn't want to box them in on dates or materials that they wouldn't prefer.
3. Cards to places the recipient frequently uses or is saving to buy something from: I'd love to help contribute to someone's new pool table, or TV.
4. I'm being a dick on purpose.
Furthermore, gift cards seem environmentally unsound.
The end result of cash gift is paper to recycle and your stuff. The end result of gift card giving is more to recycle, your stuff, and either -$ from where you spent more than the card or $0.37 left on the card, and of course the card that the cashier throws away when it's empty.
I also read a Slate article that describes gift cards as interest free short term loans from consumers. Coupling that with the fact that you almost always spend more money than the gift card's denomination, gift cards are a great deal for the conglomerates, to whom, we already give a lot of money. It seems a bit like the exact opposite of interest- one consumer gives the loan and the other pays the company a little extra later.
In closing, ba humbug!