This is hilariously over the top. I love it.

A.T. Hatto's translation is a bit dated (it was originally published in 1964), but holds up academically, in no small part thanks to the extensive critical and historical appendices included alongside the text. Hatto, himself fluent in German and having a strong background in interpretation, produced perhaps not the best possible translation but certainly the best available translation.

Translating a lyrical text is, well, impossible: George Henry Needler, whose 1904 attempt is available online, noted in his introduction that:

Translations are at best but poor substitutes for originals. A new translation of a poem implies also a criticism of those that have preceded it. My apology for presenting this new English version of the Nibelungenlied is that none of those hitherto made has reproduced the metrical form of the original. In the hope of making the outlines of the poem clearer for the modern reader, I have endeavored to supply in the Introduction a historical background by summing up the results of investigation into its origin and growth. The translation itself was begun many years ago, when I studied the original under Zarncke in Leipzig.

He continued:

The language of the Nibelungenlied presents about the same difficulty to the German reader of to-day as that of our English Chaucer to us. Many translations into modern German have accordingly been made[1] to render it accessible to the average reader without special study.

Needler's is the first English translation I attempted, quite a while ago, and found it nigh-incomprehensible (as an example, here's how Needler renders the opening stanza:

To us in olden story / are wonders many told
Of heroes rich in glory, / of trials manifold:
Of joy and festive greeting, / of weeping and of woe,
Of keenest warriors meeting, / shall ye now many a wonder know.

compared to the original Mhd.:

Uns ist in alten maeren / wunders vil geseit
von heleden lobebaeren, / von grôzer arebeit,
von fröuden, hochgezîten, / von weinen und von klagen,
von küener recken strîten / muget ir nu wunder hoeren sagen.

In my defence I didn't understand English as well).

Alice Horton's 1898 translation,[2] [b:The Lay of the Nibelungs|26759330|The Lay of the Nibelungs Metrically Translated from the Old German Text (Classic Reprint)|Alice Horton|https://i.gr-assets.com/images/S/compressed.photo.goodreads.com/books/1442838538l/26759330._SX50_.jpg|46784585], was done as a line-by-line translation of what is known as the "B" manuscript, and is available digitally online. "The additional difficulties involved in any verse-translation are so great," the preface to this edition notes,

that a translator may well be excused from facing them. Assuming the indispensable qualification of sympathy needful in the translation of any work of art from one medium to another, the differences in word-formation, in inflexion, and in grammatical construction between any two languages interpose mechanical obstacles which are inconsistent with the preservation of metrical similarity; a more or less close approximation is all that can be looked for.

In summation:[3] Hatto's is the best from an academic standpoint, but Horton's is the most entertaining.

[1] An example is the Reclam edition, which has the original Middle High German (Mittelhochdeutsch) alongside a translation into modern German. I was able to read along with the modern German text, albeit slowly, and accordingly understand most of the Mhd.
[2] Deemed the most accurate of the "older translations."
[3] Burton Raffel also "translated" a version, but we all know how I feel about his "translation," so I won't even evaluate it.