Myrmidon, over at the Kosmos Society made quite the challenge to find prayers of adoration, rather than supplication in Greek myth.
Of course, Hippolytus came to mind eventually. Our hero speaking to the unseen Artemis says,
"Accept, I pray, dear mistress, mine this chaplet from my holy hand to crown thy locks of gold; for I, and none other of mortals, have this high guerdon, to be with thee, with thee converse, hearing thy voice, though not thy face beholding. So be it mine to end my life as I began." Hippolytus by Euripides.
As I googled and read looking for such prayers all along the phrase "if ever I" kept creeping into the research. My inference is that in previous times the person using the phrase made prayers and sacrifices of adoration not out of obligation or supplication
Hear me, god of the silver bow, who stand over Chryse and holy Cilla, and rule mightily over Tenedos, Sminthian god, if ever I roofed over a temple to your pleasing, or if ever I burned to you fat thigh-pieces of bulls and goats, Iliad 1.40
make prayer to Zeus, if ever you have gladdened his heart by word or deed. (Iliad 1.390). "she spoke in prayer to king Zeus, son of Cronos: "Father Zeus, if ever amid the immortals I gave you aid by word or deed, " (1.500)
the swineherd looked the man in the face, and rebuked him, and lifted up his hands, and prayed aloud: “Nymphs of the fountain, daughters of Zeus, if ever Odysseus burned upon your altars pieces of the thighs of lambs or kids, wrapped in rich fat (Odyssey 17. 236)
When Telemachus and "Mentor" visited Nestor the aged king was in the middle of a sacrifice. As I recalled it was all rather informal. Upon research it appears the sacrifice was "off stage " and his visitors were late. But he welcomes them to join the feast after the elder of the two Mentor says grace;
Offer a prayer, sir,” said he, “to lord Poseidon, for it is his feast that you are joining;  when you have duly prayed and made your drink-offering, pass the cup to your friend that he may do so also. I doubt not that he too lifts his hands in prayer, for man cannot live without gods in the world. Still, he is younger than you are, and is much of an age with myself,  so I will give you the precedence.” Odyssey book 3
Afterwards there was a round of toasts starting with the gods
As he mixed the wine, he prayed much and made drink-offerings to Athena, daughter of Aegis-bearing Zeus.  Then, when they had made their drink-offerings. (Odyssey Book 3)
Likewise later in the Odyssey we find other non-supplicating "libations”
"We lit a fire, offered some of the cheeses in sacrifice, ate others of them. " (Book 9)
the fountain there was an altar to the nymphs, at which all wayfarers used to sacrifice. (Scroll 17 Odyssey)
Then there is the advice from Pan to love sick Psyche. Note that she offers the god reverent homage without acknowledging his help.
Cease your sorrowing, lay aside your sadness, and instead direct prayers of adoration to [Eros], greatest of gods, and by your caressing attentions win the favour of that wanton and extravagant youth.’ Psyche made no reply to this advice from the shepherd-god. She merely paid reverential homage to his divine person, and proceeded on her way." Apuleius, The Golden Ass 5. 25 ff
The Danae sang adoring hymns to the local river;
 Come now away, glorifying the blessed gods, lords of the city both those who guard the town and those who dwell about Erasinus' ancient stream. And you handmaidens take up the song. Let the theme of our praise be this city of the Pelasgians, and no longer let the homage of our hymns be paid to Nile's floods where they seek the sea, but to the rivers that pour their gentle draught through the land and increase the birth of children, soothing its soil with their fertilizing streams. ( Aeschylus Suppliant Maidens)
Demeter actually teaches someone the proper rites of adoration; “And I myself will teach my rites, that hereafter you may reverently perform them and so win the favour of my heart." (Homeric Hymn to Demeter)
This brings us to the Homeric (and Orphic) Hymns which are all prayers of adoration, along with the various paeans which people sing.