None of these six sanctuaries offers riding or shows, but they split cleanly on contact. At Somboon in Kanchanaburi and the Wildlife Friends Foundation's refuge in Phetchaburi you watch the elephants and don't touch them. Living Green, Bangkok Elephant Park, Elephants World and Elephant Jungle Sanctuary Pattaya are hands-on, with feeding, a mud spa and bathing. Decide which kind of day you want first.
The order follows welfare. World Animal Protection's elephant-friendly list comes first, then places where visitors don't bathe the elephants, then the hands-on ones, with Responsible Travel's support and the number of guides naming each place setting the order inside each group. Prices are each operator's own adult rate. Elephant Jungle Sanctuary is a paying sponsor of this site, and its place follows the same criteria.
Distance matters as much as welfare. Bangkok Elephant Park is inside the city, in Nong Chok. Living Green and the Pattaya camp are east toward the coast, Somboon and Elephants World are in Kanchanaburi to the west, and WFFT is about 160 km southwest. If you're heading north anyway, Chiang Mai has the most choice, in my guide to the ethical elephant sanctuaries in Chiang Mai.