I'm going to start an A3-sized drawing (i.e. immense for my standards), with all the Shin Megami Tensei demons I can fit in, I'll have to limit myself to the most important/recurring/personal favourite ones though.
Will definitely be featured (off the top of my head):
PC demons: Orpheus, Thanatos, Messiah, Io, Hermes, Caesar (because Polydeuces looks like ass), Penthesilea, Palladion, Cerberus (DDS/Koromaru style), Lucia, Kala-Nemi (maybe), Varna, Agni, Prithivi, Vayu, Dyaus, Izanagi, Izanagi-no-Okami, Tomoe, Jiraya, Konohana-Sakuya, Take-Mikazuchi, Kanzeon, Yamato-Takeru, Izanami
Misc. demons and personae: Pixie, Angel <3 , Helel, Lilim, Lilith, Decarabia, Forneus, Isora, Jack Frost (obviously), Nekomata, Queen Mab, Rakshasa, Titania, Yamata-no-Orochi, Ahriman, Clotho/Lachesis/Atropos, Baphomet, Berith, Black/Red/White/Pale Rider, Harlot, Cu Chulainn, Daisoujou, Dominion, Eligor, Hell Biker, Horus, Kikuri-Hime, Loa, Matador, Metatron, Mot, Oberon, Odin, Orthrus, Ose, Parvati, Power, Pyro Jack, Quetzalcoatl, Sakahagi, Samael, Sarasvati, Sati, Scathach, Shiva, Skadi, Succubus, Surtr, Thor, Trumpeter, Unicorn, Michael, Uriel, Gabriel, Raphael, Alice with Nebiros and Belial, Ares, Belphgor (on the crapper!), Byakko, Cybele, Hua Po, Ishtar, Leanean Sidhe, Masakado, Omoikane, Satan, Virtue, Yaksini, Susano-O, Attis, Chernobog, Valkyrie, Yomotsu-Shikome, Medea, Hypnos, Moros, Camazotz, Usas, Rahu, Ravana, Hari-Hara... and I think that's all of them. If anyone sees an important demon I might be missing, let me know!
... NO, Mara, you're not invited!