16:9 makes things more stretched..
Looks Stretched? It looks like you have an experience of wrong resolutions on a wide screen. If you want, you can read some of the math, which could be its cause.
When the ratio's of the screen changes, the ratio of the resolution must also be chosen accordingly. So, for eg,
for a 4:3 screen, appropriate res. would be 1024 x 768 (ratio=1.33)
for an 16:9 screen, the same res. would be 1600 x 900 (ratio=1.77)
So, as you see, res. must depend upon the screen size factor (normal or wide).
And if chosen correctly, screen would not seem stretched!