I've been using MediaTemple for hosting all of my domains for a number of years now and while I've been generally satisfied with their Grid Service I've found it a bit lacking lately. I don't have the traffic or any financial need to necessitate spending money on a high availability server but I do completely depend on email for most of my communication so when it's down or can't authenticate I feel almost completely cut off.
With that in mind I started looking for alternate hosting solutions but I couldn't find any that matched MediaTemple's feature set or phenomenal customer service (availability issues aside). Ultimately, I ended up finding Google apps mail service. The "Premier" version is essentially an third-party-hosted MS Exchange replacement that seems extremely robust. On digging a bit deeper, though, I found that they offer the Google Apps Standard Edition - a feature-lite version offering up mail, calendaring and chat all through your personal domain.
For those unfamiliar with DNS records, set up might not be as easy as signing up for a Gmail account, but other than that mail was flowing only a few minutes after making the switch.
And now I'm happy to report that a week in things are great. Being able to take advantage of all of gmail's advanced features from my own domains is pretty amazing. If you're looking for an alternative to you hosting providers email solution or interested in a cheaper alternative to Exchange, Google apps is a great choice.