Bing is an web search engine from Microsoft, Its currently second largest search engine after google.
Google is no doubt the best search engine, when you compare google with bing then bing is lacking in its performance and speed.Also in terms of relevant searches it lacks.
Apart from that it has some good feature such as daily changing background image, Video Homepage, Search results similar to google.com.
After google I would say this is the second option that you can use.Overall Bing is good, its recommended.