All. But if would have to choose just one, today, it's Elicia. Another day may bring a different choice.
I also like Biber's Requiem in F Minor a lot.
Of course, that Requiem in F minor you mention has a profound emotional impact on me:
What's more, it sometimes brings to mind other, much more famous requiems, which paradoxically were composed much later (I'm thinking of Mozart's, written almost 100 years later, or even Fauré's, written 200 years later).
Biber is enigmatic precisely because, while he composes the music requested by his patrons and in keeping with the standards of his time, he occasionally inserts totally surprising elements that bring with them a sense of ‘timelessness’ that seems to belong to both earlier and later periods. In him, you find both Monteverdi and earlier composers, as well as the development of new elements that would become commonplace in later composers, such as Handel.
For example, I also find his Missa Sancti Henrichi to be of great interest. Although it seems like a younger sister to his ‘colossal’ Missa Salisburgensis, I actually find it much more interesting. For me, it conveys a kind of perfect balance between luminosity and simplicity, poise, and peace of mind. Don't be dazzled by the typical fanfare of natural trumpets (in C) and timpani, but look at its inner lines, already in the Kyrie itself (and then you can move on to the famous Amen from Handel's Messiah 50 years later):
One thing that fascinates me about Biber is that he sometimes seems to resurrect the concept of fractality in the complete enveloping sound space that dominates at a given moment. Not the same as fractality in the musical timeline, but rather like nesting within a basic pattern at a time (fractal 1 - canon) of increasingly colorful and complex fractal levels that reinforce the strength of the essential ‘energetic’ pattern. Which leads me to connect it with this (Ockeghem) 200 years before him:
(Note: It is striking that several performers and listeners have reported hearing notes (harmonics?) at the climax of this piece that are not being played by anyone, but are purely the result of resonance.).
Now go to the Gloria from Biber's Missa Sancti Henrichi and listen to the part ‘Qui tollis peccata mundi...’. When you come from all that before, you simply close your eyes at that moment, and the little nested scales make you cry.