I'll just copy and paste what I said last time I saw this topic.
Charizard (M) @ Petaya Berry
Trait: Blaze
EVs: 12 HP / 252 Spd / 244 SAtk
Timid Nature (+Spd, -Atk)
- Flamethrower
- Hidden Power [Grass]
- Sunny Day
- Substitute
Bring him in on something like a predicted CBgross EQ, Sunny Day on the switch and Sub next turn. With these EVs you get 300 HP which is divisible by 4, so after SR damage and a single sub you will activate Petaya. Alternatively, you can max Sp Atk, put 4 EVs in defence and use a HP IV of 30, giving you 296 HP for the same effect.
If the switch in was a Blissey who tried to T-wave you, the sub will block the T-wave and Flamethrower is a 2HKO on Blissey with Petaya Boost, STAB, Sunny Day and Blaze in effect. Gives you an idea of how much damage this guy can put out.
The nice things about this set are
1) It makes SR damage work in your favour by activating Petaya and Blaze faster and
2) It clears Sandstorm
Pretty nifty.
Solarbeam is very dangerous because when Charizard Sunny Days, many opps will go to T-tar. If you select Solarbeam as they do this, you will be locked in to charging Solarbeam, do crappy damage as the power is cut in half by Sandstorm, and die to a Stone Edge while unable to switch out.