I'm currently using GoogleDrive and I'm happy using it as it's familiar and a trust worthy website for others to download voicebanks, but would there be a preferred hosting website for voicebanks?
Straightforward sites without too many advertisements are always nice to download voicebanks (or any files) from. Along with Google Drive, Box, DropBox, and MEGA are good choices. I've recently been using Keybase since it allows anyone to access my public files as if it were a folder on their own computer, though because of the encryption, transfers are quite a lot slower compared to using a website.
Also just gonna be a plonker in here and suggest putting it up for torrenting if you don't mind it being on the internet for eternity
But yeah I use MEGA to host all my files
The tough thing about torrents is that it'll always be that one version of the voicebank, and it'll be harder to put out adjustments and updates. The old versions of the voicebank that still have FRQ glitches, OTO errors, etc. will, by definition, still be circulating between users. But it can at least prevent voicebanks from being permanently lost, as long as there's anyone seeding.