It’s the last day of the Church year, so it’s the perfect time to sing the Te Deum laudamus.
Here’s a recording of the Schola Cantorum of Milan. It comes with a display of the Gregorian score as found in the Graduale Romanum book (simple tone), so you can sing along:

But why stop there? Here’s an enormous force presenting the setting by Berlioz:

And the bold 1936 setting by Zoltan Kodály, written to commemorate the 250th anniversary of the liberation of Budapest from the Ottoman Turks:

Here, the choir of Notre Dame de Paris sings one of the Gregorian settings in the presence of Pope Benedict XVI. Notice a Notre Dame tradition at work: during some phrases, the choir is silent, letting the organ “sing”. As it happened, some members of the congregation, probably not familiar with the tradition, sang those phrases anyway. (And that’s OK: it’s a good thing that the congregation knew the Te Deum well enough to sing along!)

There are several Gregorian melodies for the Te Deum: simple and solemn Roman melodies, and simple and solemn monastic (Benedictine) melodies, so don’t be surprised if a particular chant performance doesn’t match a score in front of you. Do the Dominicans have their own melody, or the Cistercians? What about the Carthusians? Maybe some more versions will turn up!