Well, I got Assassin's Creed free on the Revelations disc, which meant i was able to finally play it again...
And I was given Twilight Princess as a gift (that I had to wait to play for six months, because I had to wait for the Wiis to be restocked before they got me one...)
Majora's Mask is still one of my favorite games (but it, too, was given to me without what I needed to play it... had to wait 2 or 3 years before I found an expansion pak, and I had to buy it myself...)
So the best game i got 100% free that didnt have negative qualifications would have to be Chex Quest
I'm from Chex squadron, and I fucking volunteer