Honest to god this is my team:

1. Arceus. lv 99
2. Celebi. lv 100
3. Mew. lv 98
4. Darkrai. lv 100
5. Giratina. lv 99
6. Heatran. lv 100

Iv'e played this game for hours and hours and nobody in the world has beaten me so far. This is the ultimate team in pokemon pearl.