Narayana, Rama, Krishna, Vishweshwar, Balaji, Lakshmipati, Shesh-Shayee, Satyanarayana, Lakshmi-narayana and hundreds more.
Vishnu is depicted in many forms. Since he s the one who has taken avtar as Rama, Krishna, etc. These are many popular forms of these Avatars. He is also shown as reclining on a great Serpent (Shesh Naag), with Lakshni nearby, in “Ksheer Sagar”.
Vishnu is one of the three main aspects of the supreme Lord; the other two are Brahma and Shiva. Vishnu represents the principle of preservation of the universe in its dynamic form. All things in the universe come to existence, stay for a while and then get destroyed of dissolved. This is true without any exception. It is true not only for things, but also for being, ideas, events, concepts etc. it is due to the power of Vishnu theat things remain in existence. His Shakti Lakshmi of prakriti (nature).
Since Vishnu is the preserver of the universe he takes incarnations and comes to Earth when necessary to preserve the good and to remove the evil. Thus, he restores the balance. Men who live by followings Dharma (eternal Values), are also doing similar things as Vishnu. Rama and Krishna are the most adored and worshipped incarnation of Vishnu among Hindus. Rama establishes an example of an ideal human being (events described in Ramayana). Similarly Krishna’s incarnation shows the various paths leading to divine-love and God-surrender while living in the world (the Bhagavat Geeta, the Mahabharat and Srimad Bhaagavat Purana). By carefully studying and understanding the events in the lives of these incarnations and following their messages, we also can become God-like while still alive.