Let’s vote on the other white bracket semifinalists:
An NPM top-25 best known as an art song rather than in the older form of plainsong with the full text, Sacris Solemniis. The final two strophes begin at 3:04 in this media link.
The Easter hymn is a variant of the traditional chant Surrexit Christus. But it’s not the only development from the original. Here’s an English Renaissance setting performed by New York Polyphony.
Catholic Sensibility 
Hi, just to set the record straight: The setting of Surrexit Christus you’ve linked to was in fact composed by me in 2009; despite its medieval “flavour” it is very much a modern piece. Not that this really matters, just for the interest of your readers.
Best wishes, Andrew Smith
Thanks, Andrew, for the clarification. I was trying to find a track listing for the NYP cd, but I was unsuccessful. But it’s good to know that today’s composers are standing on very firm ground indeed with art like this.