Lets look at Charizard and Zapdos:

Zapdos: 90hp
Basic pokemon  
Electric Type
Weakness: None
Resistance: Fighting
Retreat cost: 3
Moves:
Thunder: [EEEC]Flip a coin, if tails, Zapdos does 30 damage to itself(60)
Thunderbolt: [EEEE]Discard all energy cards attached to Zapdos in order to
use this attack(100)

Charizard: 120hp
Stage 2 pokemon
Fire type
Weakness: water
resistance: Fighting
retreat cost: 3
pokemon power: Energy burn: Turn all energy cards attached to Charizard into
fire energy
attack: Fire Spin: [RRRR]Discard 2 fire energies in order to use this
attack(100)

Charizard is a stage 2 while Zapdos is a basic pokemon. ZAPDOS
Zapdos      1
Charizard  0

Charizard has 120hp and Zapdos has 90hp. CHARIZARD
Zapdos      1
Charizard  1

Charizard has a weakness to water and Zapdos has no weakness, both have
resistance to fighting. ZAPDOS
Zapdos      2
Charizard  1

Retreat cost, both have the same retreat cost. TIE
Zapdos       2
Charizard   1

Both need 4 energy cards to do both attacks, because of Charizards pokemon
power, Charizard can use energy of any type. CHARIZARD
Zapdos      2
Charizard  2

Charizards move that does 100 damage only has to discard 2 fire energies,
Zapdos has to either discard all of its energy cards or flip a coin, and if
its tails, it does 30 damage to itself.  CHARIZARD
Zapdos      2
Charizard  3

So people, as you can see, Charizard is better than Zapdos.