urgent need to know

Solution
No. ;)
Oh, alright...
It depends on the display itself.
IF it is a flat panel you should use its native (advertised) resolution, anything else just looks poor and you'll probably need to use Anti Aliasing to resolve the problem, which will greatly reduce the performance of games.
If it's a CRT then just us whichever looks best to you, these old monitors don't display in exactly the same way as flat panels and scale resolutions better.
No. ;)
Oh, alright...
It depends on the display itself.
IF it is a flat panel you should use its native (advertised) resolution, anything else just looks poor and you'll probably need to use Anti Aliasing to resolve the problem, which will greatly reduce the performance of games.
If it's a CRT then just us whichever looks best to you, these old monitors don't display in exactly the same way as flat panels and scale resolutions better.
 
Solution