Love at first sight is sort of seeing the love when beauty strikes the eye heralding the outer attraction.
Love at first site is more of finding the love in a special place unexpected beckoning the sweet moment.
Love at first kiss is sensual discovery of love most sensuous touch that tingles every nerve of the body and soul.
Love at first hug is an emotional drive that expresses the love in a mutual bearing of respect. Alas, whatever ways love is found its degree highly depends on self on how one feels the kind of love for love is the thing everyone feels.