Your search covers more than 8 billion URLs. - Google's index, comprised of more than 8 billion URLs, is the first of its kind and represents the most comprehensive collection of the most useful web pages on the Internet. While index size alone is not the key determinant of quality results, it has an obvious effect on the likelihood of a relevant result being returned.
You see what you're getting before you click. - Instead of web page summaries that never change, Google shows an excerpt (or "snippet") of the text that matches your query -- with your search terms in boldface -- right in the search results. This sneak preview gives you a good idea if a page is going to be relevant before you visit it.
There's an online tool to check your Google PageRank. The PageRank is indicated by a horizontal gauge; moving your mouse over that gauge will reveal the specific value of your PageRank.
You can get it, even when it's gone. - As Google crawls the web, it takes a snapshot of each page and analyzes it to determine the page's relevance. You can access these cached pages if the original page is temporarily unavailable due to Internet congestion or server problems. Though the information on cached pages is frequently not the most recent version of a site, it usually contains useful information. Plus, your search terms will be highlighted in color on the cached page, making it easy to find the section of the page relevant to your query.
See complete list of benifits here.