Comment KeePass (Score 1) 107
Not a complete filesystem-level solution. But I'm pretty happy with KeePass for sensitive stuff.
Using the KeePassX client on Linux, with the
KeePass2Android on our phones. We have a secret key not stored on Google Drive, and a passphrase to unlock that. Haven't had any trouble with the automatic sync of the
If encfs works fairly well on Linux, what's stopping you from getting http://linuxonandroid.org/ working on Android and mounting your encfs file in a full Linux chroot environment? Then on Windows just run a Linux VM that exports a Samba share of the unencrypted files.
The other thing I've always done since forever is just use my phone / internet kiosk to VNC+SSH back to my home PC.