The Miami one is my favourite. Colors and stuff looks nice. The rest are too blended where you can't exactly make out what all the blended jumble is. So yeah, they all look good, but the Miami one is my favourite.
I think the three individuals are best, but only because the animation one is distracting when you're reading someone's post or looking at a banner, but it is good. My favourite is the Miami one, because of the colours and the text. The Hurricane football one is good but I don't think I would have chosen that colour green. The Miami Dolphins one is my least favourite because of the colour.