Synanthic and Prohibit are considered two of the stronger wormers, but don't over look Coccidiosis, which is not reated with regular wormers. Liver flukes are only treated with ivermectin Plus.
I also really like equimax horse wormer or quest Plus horse wormer. Dose at 2 x the recommended dosage for a horse. So a 100lb goat would get a dosage for 200lbs of horse. Can go up to 3x the dosage.
but like Ksalvagno said, it does matter what parastie you are dealing with.