I just took the characters I liked in Cross, and had fun using. Serge, Starky, and Grobryc were my choices.

Trigger, I just put together a party that went well together that was fun as well. My strongest team ended up as Crono, Robo, and Magus. Pump all your magic tabs into Robo, except a few for Crono, and give Robo 2 or 3 speed tabs.

After Mother Brain, he has average speed, and good magic defence, and a high Magic power. In addition, he already has high strength, MP, and defensive abilities. With the higher magic, he becomes a beast. He can attack with any element effectively, outside of water, and his heal beam will basically max your whole group out.

And even when out of MP, his attacks hit hard, and with his physical output is still crazy.

Essentailly, this is a group that can hurt any group of enemies for a massive amount of damage, especially ones weak to lightning or Darkness.