I personally think that giving cash is just fine, and greatly appreciated. Yes, there are those that like to buy a sweater or clothing item and wrap it because it seems more personal. But, unless you are making the gift yourself, why not put the cash in a card and let them pick out exactly what they want (or many times what they NEED). No one wants to tell you that they really need to buy a tank of gas, but it will get them to their job for a week--and it is GREATLY appreciated.
I think if you put thought into the card, or you put a little cash in with the homemade gift (cookies and cash is always good for a college student), the recipient will be thrilled. They are NOT going to say "grandma doesn't love me, she just gave me cash." On a final note, if you try to buy electronics or video games, you easily could get the wrong one and returning the items or exchanging can be next to impossible. My two teen sons love a gift card, but cash is even better!