Look around for the legendary Pokemon.
One's I've found that have great overall stats (3/4/5 stars) are Rayquaza and Entei.
They're pretty good at everything, but there are other Pokemon I can't remember that also have 4/5 stars in all categories. Note that you will never find a Pokemon with perfect 5 stars in every category because I'm sure they didn't want a Pokemon with maxed stats.