In BioWare's latest masterpiece, you really do have choice. Since it does away with traditional morality, your decisions are based on something more than a cursory, binary choice at the outset. They're based, much like in the real world, on the way the decision is presented, on your relationship with those around you and on pure instinct.
And your choices rarely bring the kind of tangible rewards that games of this sort have made you accustomed to. The ripples of your decisions come in the form of clever, thoughtful writing delivered by some really fantastic voice-over artists. For my money, a game that makes you act a certain way because you're worried about hurting an imaginary person's feelings is a lock for any top 10 list.
Of course, DA:O does plenty of other smart things. There's a crazy amount of customization that really lets you play the way with which you're most comfortable. Don't like how your teammates are behaving? You can alter every facet of their tactics. Still unhappy with them? Well, there are so many potential partners that you'll never have to utilize someone you're not crazy about.
Besides highlighting how alternate choices affect the world in different ways, BioWare's also added a staggering amount of replay potential with the origins system, which provides six completely separate openings to the game, as well as unique narrative threads that set each of the race and class combinations apart from the others.
Okay, I'll grant you: It's a graphical dud, menu navigation is cumbersome on consoles and the persistent blood is terrible. But BioWare has taken digital homunculi, little more than 1s and 0s and disembodied voices, and made me genuinely care about their opinions of me. If you can't honor that kind of miracle working in a list like this, then where can you?