I found all five seasons as subs in various torrent feeds. After S is Super S (Bishicorn!) and Stars (Yay, transgenders!). 200 animated episodes total.

Rumor has it a reboot anime is currently being aired in Japan and will be imported sometime soon. There's also a live action series, which I need to find, as it will be the first season told rather differently. I saw part of one episode where Live Action Mercury is kidnapped by the Dark Kingdom and corrupted.