Super Metroid: I had absolutely no idea how this game was going to be when I bought it as a kid.
Xenogears: I knew it would be great because it was an old squaresoft game made during their golden years, but I had no idea just how great. The story floored me. The size of it alone is enough to be memorable.
I can now add FF Type 0 to this list. Such a bad set of excuses reviewers and gamers gave this game.
Lube Me Up