Given that you've suggested 24" might be too big for you, i guess you're looking at the 20" models more. The larger screens would certainly be nice for movies and for office/image work, but may add an extra strain to your gaming, not to mention your bank account
Out of the 20" models you have left you have three quite different ones to choose from. You have the NEC using AS-IPS panel technology, the Samsung using PVA, and the Asus using P-MVA. If you're not familiar with what the technologies offer i'd suggest having a read of
this which should help you. The NEC 20WGX2 is widely regarded as one of the best gaming TFT's in the market right now and is very good in terms of looks and in terms of features. The dynamic contrast (Advanced DVM mode) and OptiClear coating are very nice for enhancing games. The screen does offer decent colour reproduction for your image editing, but the glossy screen coating is not really well suited to movie watching. I found it a little distracting for this use, but many owners do not find it a problem, it's all down to taste. (my review of the NEC 20WGX2
here btw).
So that is a good choice for the gamers out there, but might not be as suited all round as you were hoping. The Samsung 215TW using a PVA panel is a nice choice, certainly a very functional screen and well designed (it has a lot of adjustments in terms of ergonomics). However, the panel is a little behind that of the NEC and other 20" models (despite the low quoted response time) and so for gaming, it's not quite as good. Colour accuracy is still good though, but movie playback is pretty noisy due to the heavy use of overdrive technology. This and the NEC are pretty noisy when it comes to video playback, but not really an issue on either as long as you are viewing from a couple of metres away. The Samsung uses traditional AR coating, so it's not as shiny as the NEC.
This leave the Asus, using the 8ms P-MVA panel from AU Optronics that is also used in other models like the Belinea 102035W and Viewsonic VX2025WM (worth a look if you decide this technology is for you). This offers some very good all round performance really. Not quite as responsive in practice as the NEC, but still very good, and a little better than the Samsung 215TW. Colour accuracy is good, and black depth is also good (black depth is a notch about the NEC). Movie playback is also pretty decent, free largely from the noise you get on S-IPS and PVA panels. Basically, this panel is good all round, not the best in all areas, but an excellent all round compromise. Assuming you like the look of the Asus (which i think is important in any choice), then this might be well suited to your generall all round needs. Might be worth checking out the Viewsonic or Belinea too, since they use the same panel.
You may also find
this article useful as it compares the 20" market and the technologies a little more
