Earth is noted to be a fairlu small planet by multiple alien characters like King Cold. Makes sense when multiple planets like Jupiter and Saturn are far larger than Earth and they're in our solar system.For an Earth sized planet probably Vegeta. Realistically a lot of weaker fighters should be capable if 21st Roshi was able to blow up the moon.
It says "if" not "with"There is a guidebook that claims it takes a power level of 10,000 to blow up an Earth-sized planet. In that case, Saiyan Arc Goku with a Kamehameha should be able to pull it off.