Kind of an off question for LCDs. It's hard to tell from the photos but I'd be willing to bet that native res with less or no AA looks as good or better than non-native res with more AA?
These screenshots do nothing, really. Whether AA is needed depends on the pixel pitch of the monitor, not the resolution. A 17" laptop screen with a pitch of 0.20 and 1920x1200 resolution will need no AA at all because your eyesight isn't sharp enough to distinguish between two pixels (without putting your face inches away from the screen, anyway). OTOH a 24" 1920x1200 monitor will definitely require AA because it is easy to see the outlines of pixels at normal viewing distances.
wow. after years, intelligently answered for myself
I am a fan of slight aa. like 2x. anything more than that isnt normally usefull without a bigger performance hit on a high quality CRT. AF is where it is at maxed out. Now that HDR is around, AA has less of a place. I wonder if AA will be back in action in dx10 later titles.
really it would depend on your video card, a high end video card is recommended for a 24 inch lcd panel, 1900x1200 resolution puts an nvidia 8800gts to task as well as it's ati cousin.
go for a card with at least 320 but preferably 640megs.
I find it is best to always run your monitor in native resolution if possible, then start adding other things like AA as your video card can handle. I don't think any amount of AA would make up for the blurring/distortion you get for being out of native res (unless it is correctly scaled ie 1/2 native res.. but that would be 960x600. ew).