My favorite is Groudon, i have a sun team in emerald, bellosoom, shiny Vileplume, Blaziken, Weezing and Armaldo.
Groudon base stats on attack and defense are Kyogre's base stats on sp. attack and sp. defense, and vice versa. Speed and HP are the same.
However, the appearance of these legendaries are much different, Groudon is the heaviest pokemon ever, and it stands on the ground.
While Kyogre is definitely frailer than Groudon but because of that it can make very strong splash and headbutt, make very strong tsunami/water wave like an orca, so it deserves 90 base speed.
Thats why Groudon in game is more frail than it looks, 90 base speed is the speed of a pikachu, do i really want that? What a 90 speed Groudon is like? Have u ever seen Groudon jumping around do double team and use tail whip?? Seriously.
If that speed goes to its sp. defense, it would be a very very dense, strong and tanky pokemon.