Well before you go spending that extra 100-200 or 300-400 dollar difference remember what your getting!
Wii (duh, the loser on the left gives it away)
Now is it really worth that small of difference? Well, unless you NEED your grass to sway in the wind.
Oh and before you say: Hey thats a big difference! The 360 and PS3 ones are gameplay, where the Wii one is, so that means the 360 and PS3 ones don't even look THAT good.
Heres your 360 gameplay video, notice the grass swaying in the wind?