the most popular one we used in china for mandarine is 搜狗拼音sougou pinyin( http://pinyin.sogou.com/).
ziguang ever be popular in the past. but are you learning the cantonese? the people in hongkong like to use 速成输入法( http://www.scj2000.com/downloads.html) . if you learned the phonetic transcription of cantonese,you can use 粤语拼音输入法