Vesuvius Hetlan said:
Starcraft 2 has an interesting one. Kill all the infected colonists or defend the colonists to buy scientists more time to find a cure. Either way you're right tho'...
I JUST played that mission last night, and with it you've brought up a good point...
The evil choice in that scenario (helping the Protoss to "cleanse" the colony with fire) is far easier to accomplish. It's less stressful to run around destroying things hand in hand with incredibly powerful aliens.
However, the good choice (Help the colonists by destroying the Protoss fleet) is far, FAR more difficult. You are required to destroy three heavily guarded command posts scattered around the map before you can attack the Protoss capitol ship, fend off "Terror Fleets" that attempt to destroy the individual colonies across the map ahead of the capitol ship, AND fend of regular attacks on your base. The time crunch involved is tremendous.
That's probably one of the best examples of how a Good/Evil choice system can be done correctly. Mass Effect 2, on the other hand, had one of the most arbitrary and unpredictable moral choice systems ever.