In Emerald, my team has exceeded 6 partners, but I usually use:
-Latios, lv 100
-Milotic, lv 100
-Regirock, lv 100
-Flygon, lv 100
-Salamence, lv 100
-Gardevoir, lv 100
If Firered, my current team is:
-Rayquaza, lv 100
-Lapras, lv 100
-Altaria, lv 100
-Gengar, lv 100
-Arcanine, lv 70
-Scyther...