After Gmail, its 30gigs now. They are offering 30GB of mail storage. But this one is not from a very big company & they have registered their site (30gigs.com) for only 2 years. The user interface may look good. If anyone is left with an invitation, send me that to mail@kiruthik.com
Year back, Hotmail gave 2MB & Yahoo 6MB, now there are offerings in GBs.
Update : I have many 30 Gigs invitations left to give out 
Mail me, if you need it....