The marriage according to the Gandharva form, without Mantras and between a willing woman and a willing man, is said to be the best to a Kshatriya.
क्षत्रियस्य हि गान्धर्वो विवाहः श्रेष्ठ उच्यते। सकामायाः सकामेन निर्मन्त्रो रहसि स्मृतः॥