I assume this is for the 4th (current) gen? The best team I've heard of (that achieved over 300 victories in a row, far far exceeding the 100 needed to obtain a star for your Trainer Card) (also, this is not a team I designed ; I copied this off of the Smogon forums):
Quote:
Won 330 times:
Gengar @ Focus Sash
Trait: Levitate
Nature: Timid (+Spd, -Atk)
EVs: 6HP, 252SpA, 252Spd
-Thunderbolt
-Counter
-Shadow Ball
-Destiny Bond
Blissey @ Leftovers
Trait: Natural Cure
Nature: Bold (+Def, -Atk)
EVs: 252HP, 252Def, 6SpD
-Seismic Toss
-Counter
-Aromatherepy
-Softboiled
They're the same Gengar and Blissey from my 177 Run, but Metagross was replaced with...
Froslass @ Choice Scarf
Trait: Snow Cloak
Nature: Timid (+Spd, -Atk)
EVs: 150HP, 4Def, 248SpA, 108Spd
-Thunderbolt
-Ice Beam
-Taunt
-Destiny Bond
The basic idea is you lead with Gengar. Either with Counter or two attacks, his goal is to take out the first pokemon and be at 1 HP. Then he uses Destiny Bond, takes the next one out, and Froslass uses Destiny Bond to take the final one out.
Despite being a Choice Scarf user, Froslass has Taunt because you need to shut down those bastards that have no attacking moves (and/or spend too much time using Double Team.)
Blissey, of course, is an overall good safe switch for most situations that these ghosts can't handle. Usually, the pokemon that are dangerous for Blissey are trying to throw a fighting-type move at her, which naturally the Ghosts love to switch in to.
The trick is that, unless you're already set up to do it, this is a rather difficult team to put together. Froslass can be bred / trained in the fourth gen no problem. Gengar and Blissey, on the other hand, have to be bred in the GBA games in order to learn Counter (and Blissey to learn Seismic Toss.) (And there's also the similar potential problem of needing to make sure you have those Move Tutor moves available, if you don't have something set up already.)
Froslass's EV spread may seem weird, but I think part of the point is to only invest the speed EVs that you need, then to boost her defensive status so you can switch in more safely.
As for my actual practice using this team? It's been kind of poor up till now. I've been using
this page to know what a pokemon that's currently out might do, but I keep predicting pretty badly.