ASUS ROG Strix X570-E is the best motherboard for Ryzen 5 5600X and RTX 3060 as it provides multiple graphics support with 3 PCIe x 16 slots. It is valuable for professionals and gamers as it supports 128GB DDR4 RAM, high storage capacity with 3 M.2 SSD slots, and a reliable ASUS AURA RGB lighting system.