The Germanic language system is the best, because it's the easiest and fastest to pronounce. You have only one syllable for each note (except for Ais and Eis, which is a-is and e-is. If you'd pronounce them correctly, they'd sound the same in German [like "eyes" in English]- but, honestly, how often do you need them?). IMO the e.g. Portuguese Fa aumentado or Si bemol is a bit long to pronounce.
The German names are: C, Cis/Des, D, Dis/Es, E, Eis/F, Fis/Ges, G, Gis/As, A, Ais/B, H
And it allows to use note names for compositions. One of the most famous musical word motifs is B-A-C-H
). Dimitri Schostakowitsch (written in German) used his initials D-Es-C-H for a motif, I wrote a popsong called Cafe Bagdad and I'm sure there are a thousand more motifs in the classical world, because composers like to do hidden stuff like that.
I'm now living in Portugal/Azores for two years and play guitar in a folk music group. It's very funny to see sheets with the chords written ABC but everybody pronounces it Do Re Mi. It took a year or so until I was quick enough to adapt e.g. a spoken "Lá menor, Fa, Ré menor, Do" without using my fingers to count. It's also quite common to write A# instead of Bb, even if the song is in D minor. We all know that A# major or minor does not appear on the circle of fifths. Anyway, the Brazilians seem to like the A#-chord as well.