Srimad-Bhagavatam: Canto 11 - Chapter 1 - Verse 22

Sanskrit:

एकद्वित्रिचतुष्पादो बहुपादस्तथापद: ।बह्‍व्‍य: सन्ति पुर: सृष्टास्तासां मे पौरुषी प्रिया ॥ २२ ॥

ITRANS:

eka-dvi-tri-catuṣ-pādobahu-pādas tathāpadaḥbahvyaḥ santi puraḥ sṛṣṭāstāsāṁ me pauruṣī priyā

Translation:

In this world there are many kinds of created bodies — some with one leg, others with two, three, four or more legs, and still others with no legs — but of all these, the human form is actually dear to Me.

Purport:

The ultimate purpose of material creation is to facilitate the return of the conditioned souls back home, back to Godhead. Since this redemption of the conditioned souls is especially possible in the human form of life, naturally this form is particularly dear to the compassionate Personality of Godhead.