I like option 1 & 3, but what if you could use the domain “highscores.com” (with a “s” at the end), “highscore.net” (instead of .com), or “highscores.net” (with a “s”at the end and with .net instead of .com).

Edit: Sorry, I didn’t read your post about having the “s” at the end. Never mind then.