So I've bought plenty of Steam packs over time which include games I haven't been that interested in, like Titan Quest.
Apart from that, I bought Eternal Darkness for the gamecube about 6 months ago and still haven't got around to playing it (need to set up the Wii, and memory cards for gamecube keep getting corrupt which puts me off)
What games do you have in your collection which you haven't played? And more importantly why? Do you still desire to play them, or will they never get downloaded on your steam client?