DVD's will look better the higher resolution you go as the more pixels on the screen the better the DVD will look. But it is relative as they still look great at XGA widescreen (1200x800).
Keep in mind that UXGA is very extreme (the pixels are very small) so some web pages can have some lettering look very small. If getting as much of a spreadsheet on the screen is your goal this will achieve that but you had better have eyes like a hawk.
So, if you want to consider SXGA and don't need 128mb dedicated video consider the HPZT3000/Compaq X1000 (I like mine for my use). If the higher end video card or the 7200rpm hard drive is a priority go with the Dell 8600 (but then you have the extremes for XGA/UXGA.
Keep in mind the widescreen 15.4" LCD on both, even with XGA, will show you more columns of spreadsheets and will display more lines of code (left to right).
But it sounds like SXGA would be a good choice for you.
See X1000forums.com for the issue of getting an LCD (Hitachi) that has a lower refresh rate than others (LG or Samsung). Dell, however uses different LCD companies as well and the only way you can be sure what LCD manufacturer you have is to burn a CD with Knoppix (Linux) and that will tell you who you have.
There are software programs like Powerstrip that can effectively lower your resolution but on a LCD (desktop or notebook) you have only 1 true fixed resolution (as you can't resize pixels on an LCD) so choose carefully.
A good compromise between XGA and UXGA is SXGA which is offered by the HPZT3000/Compaq X1000 (see X1000forums.com --general section -- pinned area on resolution.
The HPZT3000/Compaq X1000 is very comparable to the Dell 8600 but it has a better keyboard (somewhat), a better case (metal bezel surrounding LCD and aluminum lid) but it does not have the ATI 9600/9700 video card the Dell has (up to 128mb dedicated video) (it has an ATI 9200 with up to 64mb dedicated video however which is decent) and you can't get the Hitachi 60gb 7200rpm screaming fast hard drive (you can install it on the HP/Compaq yourself and many have but you can't order it like at Dell).
Hi,
I'm planning to buy a laptop from DELL. More likely Inspiron 8600 with a 15.4" monitor, with a processor Pentium M 1.6. I'm planning to invest around $1700 so by the price you can clearly see that I'm getting a desktop replacement.
I'm a computer programmer and at the same time I love watching/burning DVD's movies plus I'm a lot on the road/trips. So my questios is which resolution would be better for programming and watching/burning DVD's, the WUXGA or the WXGA? I haven't heard so much about both screen so I thought I would ask for help regarding both resolutions. Is there any machine out there that you guys could recommend for my purpose besides DELL?
Thanks for your comments.

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