That's a tough question! I'll go with the Johto beast trio, because of nostalgia. When Entei starred in one of the Pokemon movies, I adored its concept and design, and before the movie I was already a big fan of Suicune and Raikou! Right now, my favorite of the three is the electric type, but the other two are not far behind. Not to say that Unova's Swords of Justice aren't amazing; just not superior. :]