Is there such a thing? I'm currently on iOS, Mac, and Windows and I am using Gmail for my email, and iCloud for everything else. I've had too many issues with syncing contacts with Google that I don't really want to mess with anymore. Also, their web based contacts/calendar interface is hard on my eyes. Out of the big 3, I'd say that Google has the worst looking interface with probably the best feature set.
I have flirted with Outlook.com, but the contact and calendar syncing for Mac is still a mess on that service. Even Outlook 2011 for Mac only supports email with no way to setup calendar and contacts with Outlook.com.
Thought about using iCloud, but the space is really limiting. I like the interface (and out of the 3, it has no ads). But I have about 3.7GB of email on Gmail and if I decide to move that all to iCloud, that doesn't leave much from the 5GB of total free space.
Gosh, I wish Outlook.com just had proper CalDAV and CardDAV support. If it did, it would be perfect.
Ultimately, I want to find a service that is preferably free and has great compatibility across all platforms. I'm willing to switch email addresses. Although I've had my @gmail address since 2004, I think I'm OK with migrating to a new primary account and letting that one die. But I haven't completely made up my mind yet, and will certainly try things out on any new platform before fully committing.
If I were to switch from iPhone, I'd likely switch to Windows Phone but may switch to Android. I use to think that Google represented the best choice for folks who wanted good multi-platform support, and it seems that they are turning away from that.
Thanks for your input.