Based on various factors such as climate, location, soil type, source of water, and budget, the best basement waterproofing method can vary. However, in general, exterior basement waterproofing is considered the most effective method for preventing water intrusion into the basement. This involves excavating the soil around the foundation and applying a waterproof coating or membrane to the exterior walls. This method provides a barrier that protects the foundation from water penetration and can help prevent moisture-related issues such as mold and mildew growth.