That's pretty good. I never knew about that one. The good references for me back in the day were Jim Breen's WWWJDIC (he's a nice guy, too) and Space ALC's
www.alc.co.jp. Space ALC puts out some good Japanese grammar books, too.
But I own a few physical dictionaries (very good kanji ones in paper form and vocabulary ones electronic), so I only use online dictionaries (which are always inferior) when I don't have those at hand.