JiWORDS/Japanese info on WORDS http://jiwords.est.co.jp/
Online English-Japanese Dictionary http://hikyaku.com/dico/onmyog.html
Rikai: the best online dictionary! http://www.rikai.com/perl/Home.pl
Online-Japanese Dictionary http://www.online-dictionary.biz/english/japanese/?word
Jim Breen's Dictionary http://www.csse.monash.edu.au/~jwb/cgi-bin/wwwjdic.cgi?1C