I absolutely love old paintings and vintage illustrations, they're my inspiration and I'd love to draw like that. Some of my favs are Kay Nielsen, J.C. Leyendecker, James Tissot, Giovanni Boldini, Alphonse Mucha and so much more!
More manga styled ones are Tsukiji Nao, Kaoru Mori(Emma/Otoyomegatari), Kazuya Minekura(Saiyuki), Ayami Kojima(art of Castlevania), Thores Shibamoto(Trinity Blood) and like every single artist on Pixiv lol... so goooood.