Which kind of poke ball is best for catching legendary Pokemon in soulsilver excluding master balls?

The best kind of Poké Ball for catching Legendary Pokémon in SoulSilver, excluding Master Balls, is the Ultra Ball. It has a catch rate of 2x compared to the standard Poké Ball, making it more likely to successfully capture a Legendary Pokémon. Additionally, the Timer Ball has an increased catch rate for Pokémon that have been battling for a long time.