Fruit Ninja - Best on iPhone
I have all 3 major systems: iPhone 4 (iOS4.2), HD7 (WP7) and HD2 (Android DesireHD currently), and have Fruit Ninja on all of them, paid version on the iPhone and Android and trial version on WP7.
I'm finding FN works and looks best on the iPhone with the Android next. The iPhone version is faster and more responsive. The Android and WP7 version both suffer from aspect ratio error...meaning a circle is oblong or football shaped rather than a true circle. And the WP7 version has a slight amount of stutter when it starts up and once in a while when slicing fruit. The Android version is almost as precise as the iPhone version and doesn't suffer the stuttering of the WP7 version.
It's ironic how the pricing is among the 3 systems. The worst version has the highest price (WP7@ $2.99) and the best version has the lowest price (iPhone@ 99¢)...lol. The Android version is $1.19.