I use ZKanji. It has compounds, animated stroke order, readings, JLPT/Jouyou levels, kanji search with a lot of options including all of the above plus SKIP and English meaning, and much more that I don't even know. If you're not yet at the level where you can use a native Japanese dictionary, I can't think of a better free Japanese dictionary with an English interface.
Edited: 2013-05-21, 10:34 am