When yanghuawawa posted this dictionary entry on Social Mandarin I've decided to share some of my other regular online dictionary resources, giving you a low down on advantages and disadvantages.
This was one the first sites I used. It is very Web 2.0 and social. I've a got a profile on there and often make vocabulary lists of new words I learn. It is comprehensive and includes many proper names. It translated many local towns in my area for example Cape Town (开普敦) with ease.
The example sentences are also great, although sometimes it does not highlight the specific word in the sentence, and also going from English to Chinese gives you so many options, that you're often dumbfounded about word to actually use and in which context. Another plus in the inclusion of Chinese-Only dictionary itself. Always interesting to see if I can get the meaning just in Chinese.
Web 2.0 and Social
Many dictionary entries
Too many dictionary entries
Loads a bit slow
Can be clunky and inefficient sometimes
This is my favourite one thus far. This blog also uses a plugin to show the pinyin of Chinese characters. The great thing about MDBG is its really simplistic and efficient explanation of words. It also "reads" sentences read well, fitting them into words. This is great for translating work. When I sit on QQ and someone says something I don't understand, I quickly copy past it into MDBG's translate option, which combines Google Translate with it's own categorizing of words. This does wonders. I quickly glance of the horrible Google Translation to get the gist of the sentences and then delve into the new words. This help a lot. For idioms this also great. It has a comprehensive idiom database and it allows you to "cut" up the different characters to see what each means, so you can understand the idioms better.
Definitions are clear
No example sentences
Can look outdated
The recent one I found thanks to Social Mandarin and yanghuawawa. IChaCha definitely wins in the examples department. It is amazingly helpful, especially if you are unsure of how to use a certain word. It provides examples of how to use the search term in other contexts, for example: I searched to swim (游泳) and it gave me the option to use dive/swimming stroke (游泳动作). This site great when used in conjunction with MDBG and Nciku as it is really focuses on specific application. It can't handle sentences though.
Examples are oustanding
Only handles words, not sentences
All three are great resources, and I use them interchangeably, depending on the situation. Recently I've moved away from Nciku, more to MDBG and IChaCha as it caters for my current usage, translating and communicating with other people on Twitter and QQ. Nciku still serves as great source if I'm unsure about new words and just as a double check. Do you have any other online Mandarin dictionaries that you use?