Regigigas
I've used Regigigas extensively, so I feel compelled to comment. Although my experience with it is all in UU, I think it will be useful since I bet most of the people writing it off here have never used it and have never faced someone who knew how to use it.
First, I think it needs to have Earthquake - it can't power through Rock- or Steel-types with Normal attacks the way Miltank can, since it lacks Curse and recovery to tank the hits with. Thunder Wave / Substitute / Return / Earthquake is usually what I go with. While Confuse Ray / T-wave / Sub may give you a lot of chances to set up, I'm not so sure it's ultimately worth it if you're just mono-attacking Normal. If you consider that your opponent will be using their best counter (duh), you have a higher probability of netting a free sub with just parahax than you do of coming out unscathed (most likely burned or hit with a Fighting attack) with parafusion hax.
The second thing, and this is very important, is that it needs to be on the right kind of team. Regigigas actually fits in very well with very bulky teams (or BO supported by Dual Screens), especially if it's not the only one spreading Paralysis. In such a context, not only can Regigigas set up on pokemon that his teammates have paralyzed, but it can spread paralysis to help it's team as well. This is especially true because the opponent is unlikely to send in an already statused pokemon to deal with Regigigas. When you add this status spreading utility to it's immense bulk, what you have is actually a team player that can aid the goals of its team by spreading paralysis and stopping sweepers, which can actually sweep if the opportunity arises.
It certainly has it's shortcomings, and it will definitely suck if you just throw it onto a team. However, don't be so quick to write it off - I've used it on a couple of teams that have gotten onto the UU leaderboard and scored victories against well respected UU players. I've never used it in NU before, but I imagine since it could do well there, too, granted it has the right kind of teammates to choose from.
@Al Alchemist
I think I would much rather use any of the pokemon that learn Agility / Taunt / Baton Pass or Nasty Plot / Taunt / Baton Pass than try to run anything with a set of Nasty Plot / Agility / Taunt / Baton Pass, much less Aipom. Aipom is just never living long enough to get two boosts and pass. Barely anything can do that, really. If you limit to one boosting move, you have awesome choices like Gligar, Floatzel, and Hypno, who can boost, taunt, and pass much more reliably than something as ridiculously frail as Aipom. Hypno particularly has a lot of untapped potential as a Nasty Plot passer, as it is quite bulky, and can take hits before passing so your sweeper gets in unscathed.
@PK Gaming
252 Atk Adamant Lickilicky +2 Explosion vs. 0 Hp 0 Def Aggron: 70.8% - 83.6%
: P