Tvameva Tat Tat Tvameva

Tat tvam asi - Thou art That

is the most important hidden message of the Hindu scriptures. In an attempt to understand GOD and realize the world we tend to look outward. Over millions of years, from the period when darkness wrapped darkness around, desire has slowly taken away life and buried it deep under the worldly pleasures. The world created thus, as viewed externally, is explained as an illusion and looking inward alone will lead to the root of all beings. The great saints like Sankara, Ramana maharishi, Ramanuja, Desika, Ramakrishna Paramahamsa and Vivekananda have travelled the million years' worth of depth inward to reach the TRUTH. They all ended with a common conclusion - That life is universal. That You are the Truth, and the Truth is You.

Usha, to answer your question from Narayana sooktam:

Sa bhrama, sa siva, sa hari, s'endra s'okshara, parama swarat.

From GanapathuaAtharvasiirshopanishad:

Tvam bhrama Tvam Vishnustvamrudrastvamindrastvamagnistvamvayustvamsuryastvam chandrama tvam bhrama: boorbuva: svarOM.

It really doesn't matter as long as you pick one and place the complete faith.
Krishna, arguably is the most charismatic of them all - "Karshati ithi Krishnaha".
He gave the Bhagavat Gita. He graced the Gopikas (gender no bar) and Yadhavas (caste no bar) who knew no rituals/agamas of worshipping but love and Bhakti. He is the most recent Vishnu Avataram. His leelas are bountless. He is the Supreme God, if you believe.
Sarvam Krishnarpanamastu.