I can’t remember what the rest of my party usually is. I don’t play power-teams, I just keep who I like with me. Gyarados has been my favorite ever since an RPG that let you play as trainers or pokemon about ten years ago. The first character I made when the new version came out with GSC characters was Gyarados, and it was a shiny, so I’ve always had a red gyarados with me.
It also got me through a bunch of matches in GSC.
People may laugh, but if I could this would be my team. I pretty much always play only with the starter (water one obviously) beating EVERYTHING with it. In Soul Silver I even beaten all of Red’s pokemon using only my lvl. 100 Feraligatr. Aside from the starter I hold in my party only HM Slaves (I even had Ho-oh with Fly…).