Personally I use http://fastmail.fm.
Been using it since 2002 with never a problem. Nice text-based (no ads, no flash or graphics) web interface which means it is sill usable on even the direst connection.
Full IMAP access, ability to write IMAP sieve scripts, have virtual domains, multiple “sent from” aliases, DNS records. All that useful geeky stuff.
Plus it’s not GMail (they know more than enough about me already!)
Only downside is that you have to pay for it and storage is limited – both of which seem a little anachronistic in these days of free unlimited everythings.