Ok here are my combos:

#1 Venusaur+Exeggutor:
This combo works because of both being grass types.(Venusaurs power 
helps GRASS pokemon)As you probably
all ready know Exeggutor's part in this is Big Explosion:Flip a coin for 
each energy on Exeggutor and for each heads do 20 damage.
Very good attack on it's own. But, combined with Venusaur's Pokemon Power:
Solar Energy the team are practicly unstoppable
(with enough energy)

2#Alakazam+Dodrio:
Alakazam's pokemon power:Damage Swap enables Dodrio's Rage Attack to 
increase with each damage counter.
Dodrio's Rage attack is as following: For each damage counter on Dodrio do 
10 extra damage 10+.
Rage isn't to good on it's own but with Damage Swap you got one good combo.

3#Alakazam+Tentacool:
Tentacool being a little used pokemon with little HP gets scoffed at but 
with it's pokemon power:
Cowardice along with Alakazam's pokemon power:Damage Swap becomes a damage 
removing machine!!!! A word to the wise you don't need to have any water 
energies to use this!!!!

4#Dugtrio(Base)+Invisible Wall:
Dugtrio's Avalanche attack does 10 damage to each of your bench so using 
Invisible Wall is
lifesaving for very weak pokemon.

5#Tyranitar+Unown"D":
Tyranitar's Trample attack can be vicious to you as well as your opponent. 
Play it safe with Unown D, you won't even have to flip for your bench.

6#Dark Alakazam+Haunter(Fossil):
Dark Alakazam's Dark Teleport attack is very useful, but most of the time 
it's bad for the pokemon you bring out gets KO'd. So Haunter's 
Transparecy Power will be very useful against pokemon attacks.

7#Houndoom(Neo3)+Energy Flow:
Neo 3 Houndoom's Dark Fire attack allows to discard a fire energy and get 
a dark energy from the discard. As you know Energy Flow puts energy from 
pokemon in your hand, so you can collect the dark energies from 
Houndoom.

8#Chansey+Unown"N":
Chansey's Double-Edge attack is powerful but dangerous for Chansey. 
Unown N's Power stops up to 30 of that damage done to you!!!!!Neat, 
Huh?

9#Pokemon Flute+Gust of Wind:
Now most people now about this fairly simple stratgy. Use Pokemon Flute
to bring a weak pokemon like Weedle out. Then GOW it and KO it in 1 20HP 
hit.

10#Ditto+Gust of Wind:
This is an ultimite pain in the neck for charizard type pokemon.(Big Attacks)
You get to choose which of your opponent's pokemon you want Ditto to 
be!!!!!

11#Snorlax+Rocket's Drowzee:
Rocket's Drowzee's Pokemon Power:Long Distance Hypnosis is good if 
you get heads.On the other hand tails is the ultimite bummer. Snorlax's Pokemon
Power:Thick Skinned gets rid of the nasty effect on you. So don't even take 
a chance. Take Snorlax. 

 

12#Murkrow+Dark Vileplume: 
This is about as mean as they get. First use a Gust Of Wind or some other
card to bring out a pokemon that can't do damage(Cleffa or Clefairy Doll).
Make Murkrow your Active Pokemon and evolve Dark Vileplume. Use Murkrow's 
Mean Look attack. Your opponent can't retreat his active Pokemon, and he
can't use a Trainer card (like Warp Point or Switch) to save it. Use Murkrow's
Feint Attack to KO the bench at will. If you strand something like a Cleffa
that doesn't have a damage-doing attack, they're doomed. 

13#TR Rattata+Here Comes Team Rocket:
Rattata's pokemon power:Trickery is ok by itself, but joined with here Comes
Team Rocket you can get the card you have been longing for.

14#Mew+Aerodactyl:
When you get Aerodactyl out, use Mew to get rid of any evolutions that got passed 
Aerodactyl.