Where's Antonioni's whatever-Trilogy of "L'Avventura", "La Notte" and "L'Eclisse", A? (I believe that it's called the "Vitti-Trilogy" sometimes). 

If "The Mother of Tears" will be good enough (20- 25 Points), I'll chose the "Three Mothers Trilogy" though then only the two first films are outstanding and I haven't seen many of those trilogies you've listed or, at least, not all three films. 

Leone's "Dollar"-Trilogy, Gus Van Sant's "Death-Trilogy" and, especially !!! of course !!! "Lord of the Rings" are strong rivals, though.