The best online dictionary?

What is the best on-line dictionary or simply dictionary?

For me, in order to learn English, it is not really easy for me to find a good dictionary which satisfies my poor English level with a very small vocabulary. I need the dictionary can pronounce, I need English explanation, and I also need Chinese explanation.

I have tried

• Dr. eye: a well-known dictionary from Taiwan (English-Chinese dictionary with example sentences, and pronunciation service). Its service is also adopted by Yahoo Kimo Dictionary.
  
• freedictionary: a free on-line English-English dictionary with pronunciation
• open dictionary: a growing open source dictionary with multi-linguistic translation
• Webster dictionary: a renowned English-English dictionary with pronunciation service and Webster Thesaurus gives the synonym and antonym services
• Dict.cn: This is my current favorite on-line dictionary with English-Chinese, Chinese-English and English-English dictionary along with the example sentences. The pronunciation service is provided as well. In addition, it sometimes gives synonym. Some of its disadvantage for me is the support of big5 (Traditional Chinese) is not perfect with very little bugs sometimes but bearable.