I have been hunting for laptops and have narrowed my options down to a short list of 2, both of which were made by Acer and share almost all of the same components, as well as boasting similar prices (albeit the smaller one does have a slightly better processor). However, they differ in two respects: screen size and resolution.
The first one is 1366x768 and has a 15.6" screen. The other is 1600x900 and has a 17.3" screen.
Let me clarify that I have no real preference for size; it is not a deal maker or breaker. I do not plan on carrying it around much, but at the same time it will not be acting like a desktop replacement.
My question boils down to this: will one provide a noticeable higher quality than the other, particularly the latter over the former given the small size increase? Furthermore, treating each one irrespective of the other, how would you consider the resolutions for each if used for light gaming and browsing?
1366x768/15.6' is kind of the default resolution and size for a regular laptop. It will perform better in gaming than the 1600x900. On the other hand, 1600x900 will look better. In my opinion, you won't notice that much of a difference until put them next to each other.
The 17" will require more graphics horsepower to get equivalent FPS. If they have the same GPU, keep that in mind.
...although if, by "light gaming," you're referring to 2D games or online Flash games (e.g. Farmville), it won't matter much.
Personally, I like higher resolutions. I feel that 1366x768 isn't a high enough resolution for a 15'' screen. And as Geofelt mentioned, you can always reduce the res in a game but you can't increase it.