I bought Okami for a friend, ages ago.
And I remember finding some sort of rollerblading game on PS2 for another friend who really liked the demo but could never find the game (it was pre-owned and cheap, but he enjoyed it). I gave my copy of LEGO Star Wars II to this same friend, because I bought the complete saga, and he's a Star Wars fan. Doubt he ever actually bothered playing it even though I'm sure he'd enjoy it.
I grabbed Prey as a part-gift for someone else because it was only £4 and I think he liked the demo.
More recently I got Ghostbusters on Wii for my sisters.
Pretty sure I must be missing some stuff. I'll have to think on that. Generally, friends and I have enough money to buy what we want when it's available.