Well, let's see. Trying to go away from the norm, I may go with Clefable - "A jack of all trades but masters of none" as some sites say, but one cannot deny its sheer versatiliy. From its wonderful movepool to a very great Ability in Magic Guard, Clefable is one of my favorites if I were to make a team of 6 of the same Pokemon.
- You can have a physical sweeper set up with a Toxic Orb/Facade combo, as Clefable will not be hurt by Poison thanks to Magic Guard, and it also gets STAB for said boosted Facade. Meteor Mash and Brick Break also make nice physical fillers too.
- It can also be a stalling tank in roughly the same manner as a Blissey, being able to learn Softboiled (Fire Red/Leaf Green/Emerald Move Tutor) and Seismic Toss. Basically, it can do what Blissey can (save for Aromatherapy/Heal Bell).
- Of course, it's also a nice statuser, as it can learn Thunder Wave and Toxic. Paired with Softboiled/Wish and Substitute, it can stall many things. Of course, this leaves it without an offensive move, so you can either replace a move with Body Slam/Facade or rely on the other Clefables.
- How can I ever forget a special attacking variant? With a wonderfully diverse special move pool it can learn moves like Ice Beam, Thunderbolt and Flamethrower. All it'd need is a Special Normal move (which it lacks). Life Orb can help a bit too, or Expert Belt, since it'll have some nice coverage with its diverse special set. You can give it Grass Knot too, though Thunderbolt and Ice Beam can handle what Grass Knot can (save for Swampert).
- Then there's the random Clefable set. Teaching it Fake Tears, Charm and Metronome will keep the opponent guessing what'll happen next. Of course, such a set will be a "double-edged sword" as it may not go your way and can end up hurting you than helping you. But that's the fun of the "dice roll" in my opinion
- For the last set, I'd go with an all out supporter. Stealth Rock is always welcome, and having Wish on it will allow it to heal other party members. Thunder Wave is for paralysing or Toxic for watching the opponent rot, whilst Ice Beam being the last move for an offensive option that you can never go wrong with.
There. That should do it. Clefable may not be strong in terms of stats, but as I said earlier, one cannot deny its versatility. The fact that it can perform things that a Blissey can (not as well of course) makes it all the more attractive as a versatile Pokemon. A team of nothing but Clefables may or may not win battles, but it'll still be fun to mess around with, and fun is what counts in the great scheme of things, no? :3