The only game I've seen with any kind of sampling option built in is Guild Wars 2, which lets one run the game at a much higher/lower internal res with the effect of sharpening/softening the image and affecting performance accordingly. This doesn't affect the output resolution on the monitor, but it's surprising how strong the visual effect is.
I haven't otherwise tried this myself, but you do remind me that an nVIDIA driver update added a setting for this under the name 'dynamic super resolution'; it can go up to x4 native resolution, but can't go down and upsample. I think this works best on old 3D games. I had settings for X-Tension that gave it x16 anti-aliasing and such, and it gave the game a very clean and defined appearance. Quite nice that we can make old games look that little bit better through rendering techniques.
1024x720 isn't 4:3, by the way. That would be 1024x768. I guess 1024x720 is the 14:9 compromise ratio... which I just looked up and learned about. Whenever I need a new monitor I might go for one like that if it ends up being less trouble to find than a 4:3 one.