Agreeing with Molk that Rhydon is, in fact, the best. It tanks hits like it's its job and retaliates with equal force. It's also very versatile, being able to alter its EV spread and moves significantly to adapt to handle different threats. It can run offensive sets like Choice Band and Rock Polish, and can also run enough Special Defense to take on weak special attackers like Rotom. My favorite set is offensive tank that I've been using since BW1, but I also like a more defensive set because Absol is a threat to a lot of teams and Rhydon is one of its best counters.
However, this just reminds me how bad these stats are, even with weighted ones. I feel like the RU ladder metagame is completely different from the actual RU metagame, which honestly defeats the point of having a ladder. While the stats are better than before, having mediocre Pokemon like Hitmonlee, Typhlosion, and Sandslash much higher than actually good Pokemon like Escavalier, Poliwrath, and Rhydon. This all kinda stems from the fact that RU had the highest average weight of any BW metagame bar Ubers, while the ladder is known to have very few good players on it. Weighted stats are a start I guess, but part of the reason they were designed for is to stop this kind of thing, which hasn't really worked out (except UU Nidoqueen, that is very good).