In these last five, the second image is quite a lot different than the others. They seem to be awash in a slight yellow-orange cast. But the second image has the truest color for sure. Just look at the yellow seat on the toy bench in the background, and you'll see that the others have a yellow that tends to slightly orange on the color wheel, while on the "better" second image, the yellow seems to be a truer lemon-yellow. Also, the grass is another indicator -- the second image's grass is more into the blue spectrum than the others. And the fence has obvious "gold" tendencies in 1, 3, 4 and 5. Again, #2 seems to have the best overall color.
I'm thinking that if you bring up Hue/Saturation and go to the yellow channel for the ones other than the second - maybe try knocking down the hue a little. Then bring up the blue channel and cut the saturation about 5-10 points.
Remember though, that this just the way I see it. Other viewers can and will have different opinions, so I give this to you with the thought that only you can decide which is the "truest".
Good luck, and I would like to see some more tweaking. If you would like to give me a shot at trying the tweaking, I would be glad to attempt it.