The key is not to try to go to the highest resolution possible.

Planescape looks stunning to me at higher resolutions, whereas I find the original resolution to be awful.

Your problem has nothing to do with widescreen vs. 4:3 aspect ratio, it is a matter of high vs. low resolution.

Regarding ratio, the only games not originally made with widescreen support that usually benefit from it, are FPS/TPS games, and only if the widescreen fix is Horz+ (wider viewing angle) rather than Vert- (upper and lower edges of the image cut off). Other games like RTS games may benefit as well, provided the widescreen ratio actually makes more of the ground visible.

Higher resolutions however, generally only benefit 3D games. With those, game objects scale along with the resolution. Games that use bitmap graphics don't have that advantage. As the resolution goes up, all game objects become smaller. This can be fine if you just raise the resolution moderately, but usually results in the game becoming more or less unplayable if you raise the resolution dramatically.

Also, higher resolutions won't necessarily make 3D games look better, sometimes the opposite. Older 3D games used much fewer polygons in their models than modern games do. A model that looked fine in 800x600 on a CRT monitor will almost certainly look like crap rendered in crisp 1920x1080 on a high quality LCD display.

And even if 3D models don't get pixellated when they are scaled up, the textures they use, do. Which looks even more out of place in high resolutions.

So basically, what it boils down to in both the argument of widescreen vs 4:3 and of high vs. low resolution, is that it depends on the game, and in the case of resolution it also depends on HOW high resolution we are talking about.

Currently when using HDMI on nVidia drivers there is no way to maintain 4:3 ratio, sadly. This makes widescreen hacks and tweaks almost essential for me to avoid very obvious stretching. I am playing Morrowind right now and even though the widescreen hack for it is Vert- I still use it to avoid stretching a 4:3 image.

You sure. I have a 24" 1920x1200 monitor but can play games at 1280x800, such as Baldurs Gate. As you say, at the native res of the monitor it's near unplayable. But at lower wide-screen res it looks great.

I have a GTX 460 and it doesn't seem to support anything lower than 800x600 by default. But can also add custom resolutions, but it's still a little problematic at times running at games 640x480 for example.

Whoa, I really disagree with this.

My 1080p monitor supports aspect ratio scaling by itself, so I usually use that in preference of NVIDIA's anyway. It does fail for some resolutions though (1440x1080 not supported, 1600x900 somehow becomes 1440x900, 640x480 cuts off the bottom).

Try to ignore the small player character which is mostly just a green shape because his back is turned, and look at the other 98% of that image. Can you honestly say you think that looks great? And how many examples do you think I could find where even the player character (or other characters) looks absolutely horrible?

Yes, I have tried smaller resolutions and my monitor scales it to a muddy, fuzzy mess. The only time its built-in scaling seems to look OK is if I force fixed aspect ratio scaling through the graphics card drivers and use the game's default/original res.
I could add it, but see the above.

There's a big difference between 'dated' and 'horrible'.

Yeah, definitely, I think it looks great. But I guess I should clarify a bit - no, the models aren't detailed models. However, I don't think that the game looks better played on an N64/CRT. I think it looks better at this high resolution and different aspect ratio. Bad models look bad, period. For instance, damn how I hate looking at FFVII characters when you're just running around. It doesn't matter what resolution you play that game at; the models look bad. I don't understand how resolution changes your opinion on models.

EDIT: I guess I should have just said what Tormentfan said.

Crisper and higher res is always better if you ask me. I don't get that whole "designed for low-res and looks better than way" thing. I have seen that with modern console ports as well, people saying my 1920x1200 resolution makes no difference because the games were designed for 720p and higher resolutions make them look "worse."

I really don't get that... the crisper the game looks the better, which means higher resolutions and more AA/AF make a game look better every time, no matter what. They might not make it look like a modern game, but they make it look the best it can.

Precisely what I was going to say. Say the game was meant for 640x480, if you picked 853x480 everything on your 16:9 monitor would be the same size, but you'd be using the whole of your screen (and the aspect ratio would be correct).
Of course, I don't think 853 is a permissible horizontal resolution, you might get away with 850 or if not, 800. 800x480 would get you 15x9. You'd be using almost the full resolution of your monitor but with the same level of zoom.

Another nice one would be 1024x576 if your video card will allow 576 (interestingly enough 576 is the vertical resolution of PAL video).

There are other possibilities too, I use this to calculate them: http://andrew.hedges.name/experiments/aspect_ratio

EDIT: I should point out, you need to add them as custom resolutions in your graphics card control panel and then choose them in whatever resolution hack you use.

Look, for the sake of presenting the argument, I probably draw the lines a little sharper than I actually think they are. Also, I'm not saying that this is the rule and there are no exceptions. And finally, when all is said and done, "better" and "worse" are subjective words. It is naturally a matter of opinion, and what each person focuses on.

One specific example of my own experience is Prey. When I bought the game I had a somewhat oldish computer with a dated graphics card and a CRT monitor. The machine ran the game just fine, and I thought it looked fantastic. Fastforward 6 months to where I bought all new hardware. New machine, a GTS 8800 and a 22 inch widescreen LCD monitor (1680x1050). I thought to myself that Prey must look fantastic on my new rig, so I installed it and cranked everything up. The models that looked beatifully smooth and rounded before now looked flat and obviously polygonal (if that's even a word) due to the higher resolution and clearer picture. In my opinion, it looked worse, not better. But then, that IS just an opinion.

Naturally, I have also had the reverse experience, where a game really did look much better at higher resolutions. Tron 2.0 for example (but then the graphical style of that game carries itself well at any scale). So in the end, I fall back on my original point which was, as I recall, that it basically depends on the game. Some games benefit from higher resolutions, some don't.
There is also a big difference between "dated" and "better", however ;-)

"Better" than what?

Surely you're not comparing older gfx with state of the art stuff and penalising it for being more primative?

No, but I think I inadvertently attributed some of StingingVelvet's argument to you. I meant "better than the same game in the original resolution on older hardware".