I love We Can't Stop but Wrecking Ball just wiped the floor with it in every aspect. My plays for both songs on Last FM says a lot. WB is nearing 500 plays while We Can't Stop doesn't even have 150 yet.
"We Can't Stop" is much more enjoyable if I tune out the lyrics. "Wrecking Ball" is pretty snoozy and by-the-numbers aside from the pre-chorus, so I guess I'll go with "We Can't Stop"