I have had hotmail, yahoo mail, gaggle mail, and a company email provided through yahoo....
And then, I found GMail.
I have used it for more than 3 years now.... and have not even considered switching.
I have never deleted anything.... and my total memory available is not even close to being full. I am 16... I get tons of emails... from colleges, friends, yahoo answers, the sportsman's guide, youtube, my grandma, my parents.... never deleted a single one.
I can go back and find information, photographs, documents, etc. that would otherwise have been lost.
I can organize emails easily... and even tell the system to apply a color coded label as soon as it arrives in my inbox. youtube is red, a close friend is a blue, sportsman's guide is yellow, yahoo is green....
Some annoying thing I signed up for can be filtered out into the archive without even touching my inbox...
And it is 100% free....
It is great.