There are loads of email hosts out there, but none of them can boast as many users as Google can. Gmail is the most popularly used mail system so far. This is partly because Gmail is integrated into almost all Android smartphones.
Gmail opens up the entire Google world to its user including Google Docs, Google Calendar, and Google +. There is so many programs and functions within the Google suite of applications and Gmail itself that it is hard to figure out how to get the features you want to work how you would like for them to.
I stumbled upon an article today filled to the brim with Gmail tips and tricks that I thought would be helpful to all you Google users. If you aren't using Google programs, check the link out anyway it just might convince you to switch services.