Gmail is best email site. its invention of google. Im using this from many years. first u was use yahoo and rediff mail because I was not know gmail that time.
Then I find this and stop using yahoo. its much easy to use then yahoo-mail. its totally free of cost service. now its available for smartphones too. in android phone it come in built. it every easy to use now.
We can reply important mails from phone any time and anywhere. gmails account can be use for all google services like play-store, YouTube, orkut, google+ etc etc. overall its very useful invention .