Śrī Kṛṣṇa is the emperor of the fullest rasa and Śrī Rādhā is the empress of the fullest bhāva. When we study rasa and bhāva we find that bhāva is the worshipper and rasa is the worshipped. Within this worshipped/worshipper relationship Śrī Rādhā is the crown jewel of all Vraja’s mahābhāvavatī-madhura-kiśorīs , because She can fulfill all of Kṛṣṇa’s desires.

kṛṣṇa vāñchā-pūrti-rūpa kore ārādhane;
ataeva ‘rādhikā’ nāma purāṇe vākhāne (C.C.)

“She worships Kṛṣṇa by satisfying all of His senses, hence the Purāṇas call Her ‘Rādhikā’.”

Śrīpāda Śuka Muni describes how the gopīs reveal the extraordinary status of Śrī Rādhā’s worship of Kṛṣṇa:

anayārādhito nūnaṁ bhagavān harir īśvaraḥ
yanno vihāya govinda prīto yām anayad rahaḥ
(Bhāgavata 10.30.28)

” Lord Hari Who destroys the misery of His devotees and Who fulfills their desires must certainly have been worshipped by this girl because Govinda was so much in love with Her that He left us all behind and took Her along to another place.”

From this statement we can understand what is the distinction between the worship of Rādhā and the worship of all the other mahābhāvavatī-gopasundarīs. The verbal root rādh means ‘to worship’ and She who worships is therefore named Rādhā, the greatest of all the milkmaids of Vraja to worship Kṛṣṇa. No other gopī in Vraja has such a significant name.

For instance, anything which contains water can be called jaladhi but pools, ponds and rivers are never called jaladhi by anyone. When one says jaladhi everyone will understand that one means the ocean. That is so because the ocean is the root-reservoir of all the water in the world.

In the same way all the gopīs and indeed all the loving devotees may worship Kṛṣṇa according to their own love for Him, but no one else but Vṛṣabhānu-Nandinī can be called Rādhā. Vṛṣabhānu-Nandinī is the root reservoir of all Kṛṣṇa-worship.

Again, according to the qualtity and the quantity of their love all the different devotees may be dear to Kṛṣṇa, but Mahā-Premavatī Rādhā is Kṛṣṇa’s dear most beloved for Her love is the greatest, both in quantity and in quality. Therefore Her sounds, touch and so on are the cause of the greatest relish to Kṛṣṇa, although He is the embodiment of full transcendental bliss. Śrī Kṛṣṇa says:

koṭi kāma jini rūpa yadyapi āmāra;
asamordhva mādhurya – sāmya nāhi yāra
mora rūpa āpyāyita hoy tribhuvana;
rādhāra darśane mora juḍāya nayana
mora vaṁśī gīte ākarṣaye tribhuvana;
rādhāra vacane hare āmāra śravaṇa
yadyapi āmāra gandhe jagata sugandha;
mora citta prāṇa hare rādhā aṅga gandha
yadyapi āmāra rase jagata surasa;
rādhāra adhara rasa āmā kore vaśa
yadyapi āmāra sparśa koṭīndu śītala;
rādhikāra sparśe āmā kore suśītala
eimata jagatera sukhe āmi hetu;
rādhikāra rūpa guṇa āmāra jīvātu
(Caitanya Caritāmṛta Ādi 4)

“Although My form defeats that of millions of Cupids and is unrivalled in its sweetness, soothing the three worlds, but the sight of Rādhā soothes My eyes. The song of My flute attracts the three worlds but Rādhā’s words soothe My ears. Although My fragrance scents the whole world, My heart is stolen by Rādhā’s bodily fragrance. Although the whole world is juiced up by My flavour, the flavour of Rādhā’s lips subdues Me. Although My touch is cooler than that of millions of moons, Rādhikā’s touch cools off even Me! In this way, although I am the cause of all the pleasure of the world, Rādhikā’s form and qualities are My very life!”

…

Because Śrī Rādhā is non different from Her name Śrī Kṛṣṇa is seen to be most attached to Her name as well. In the stage of pūrva rāga  we can read:

sakhi! rādhā-nāma ki kohile!;
śuni kāna mana juḍāile
koto nāma āchaye gokule;
heno hiyā nā kore ākule
ei nāme āche ki mādhurī;
śravaṇe rahalo sudhā bhari
cite niti murati vikāśa;
amiyā sāyare yeno bāsa
āṅkhite dekhite kore sādha;
e yadunandana mana kāṅda
(Pada Kalpataru)

“Sakhi! Who has pronounced this name ‘Rādhā’? When I hear this My mind and ears are soothed! How many names are there in Gokula? None of them has agitated My heart as much (as this one)! How much sweetness is there in this name? It fills My ears with nectar! Her form becomes clearly manifest in My mind and it is as if I float in an ocean of nectar! I will be fulfilled if I can see Her with My own eyes!” Thus Yadunandana’s mind weeps.

When He first hears the name of Rādhā the ears and mind of Śyāma, the embodiment of bliss, are soothed, His heart becomes agitated, His ears are showered by a stream of nectar, and the name has given to the bearer of that name a clear shape within His mind. When He hears this name He becomes very eager to meet the named One too – the name of Rādhā is filled with sweet honey.

Not only that, simply by hearing that Rādhā-nāma the transcendental youthful Cupid of Vṛndāvana Śyāmasundara feels the agitation of lust within His heart, which means that He’s actually very eager to relish the flavours of Her mādana-prema. His mind is absorbed in Śrī Rādhā and He thinks:

‘If this girl’s name is so sweet, then what must Her form be like?’

Thinking like this, He becomes very eager to see Her and He impatiently asks one sakhī to describe Her form to Him:

rādhā-nāma ki kohile āge;
śunaite manamatha jāge
sakhi! kāhe koholi uha nāma;
mana māhā nāhi lāge āna
koho tachu anupama rūpa;
bujhlam amiyā svarūpa
heraite āṅkhi kore āśa;
koho rādhā mohana dāsa

“Who has pronounced the name Rādhā just now? After I heard it Cupid awakened! Sakhi! Tell Me, who has such a name? My mind can’t think of anyone else anymore! Describe Her unrivalled form to Me; I understand that it must be pure nectar! My eyes yearn to see Her!” Thus spoke Rādhā Mohana dāsa.

When Śyāma hears even a single syllable of Rādhā’s Holy Name He eagerly wants to run up to the person who pronounced it and when He hears the second syllable He immediately runs anxiously up to that person.

The Purāṇas say:

rā-śabdoccāraṇād eva sphīto bhavati mādhavaḥ
dhā śabdoccārata paścād dhāvaty eva sasambhramaḥ

“When Mādhava hears the syllable ‘rā’ He becomes very happy, and when He hears the syllable ‘dhā’ after it, He eagerly runs (after Rādhā).”

Srila Radhakund Mahanta Ananta das babaji