With these two games being the two latest I've finished, I started thinking about similarities and differences between them, and how they fit into the scores they were given by Edge (which is basically the single biggest factor in me deciding whether I should get a game or not), which were 8 for Splinter Cell and 9 for Broken Sword.
They are both third-person games that are clearly influenced by movies. In the case of Splinter Cell: Chaos Theory it's anti-terrorism and action movies, while with Broken Sword: The Sleeping Dragon it's more easy-going adventure movies like Indiana Jones. But the approach of the two are entirely different; Splinter Cell goes for realism and action and guns, and it shows in the graphics. It's a finely polished game, and I would imagine that especially the Xbox version that I played has been tuned to perfection and the versions for other platforms have then been scaled back to suit the hardware.
Broken Sword, on the other hand, has more basic graphics, foregoing realism for a more stylised look (tying back to the look of the first two point-and-click adventure games, I've heard). It's interesting to compare the two graphically, because it brings forth an ever-true point about graphics in games: no matter how good (or bad) a game looks, you will eventually get used to it, and thereby it will seize to be a terribly important point.
This also leads to another thing that separates the two; a point where Splinter Cell falls flat while Broken Sword shines.
With the focus on realism in Splinter Cell, it falls victim to a long line of games that have tried the same that just ends up with characters that look like puppets. This is called the uncanny valley; we recognize the similarity to humans, but there is something there, or perhaps isn't there, that breaks the illusion and makes the characters look more like puppets. This is where Broken Sword excels. Using lip-syncing and facial animation, while keeping the characters derived from the hand-drawn original characters, keeps them on the same level as an old-style cartoon. It is this, in combination with the great script and voice-acting, that makes the characters in Broken Sword have more personality than the characters in Splinter Cell.
In the end, Broken Sword just made me smile and laugh a lot more than Splinter Cell. And that's what matters.