I canāt speak for solo artists since I mostly just listen to bands but Iāll say Tom Chaplin of Keane (go ahead and make fun of me but he was also invited by Queen to do covers and did it better than Adam Lambert imo).
Also not the best but I really enjoy Rose Elinor Dougallās very dry plain vocals with a British accent and Juanita Steinās vocals with a thick Australian accent.