It depends a lot on the message being sent and how busy I am. Email is great for sending information quickly that doesn't require discussion, and you don't have to spend time on small talk and platitudes.
When an exchange of ideas is required or a decision needs to be made I prefer face-to-face. The same goes for when I want conversation for conversation's sake. The phone is a weak third.
Texting is a last resort. I don't enjoy the mechanics of it, nor do I like writing in abbreviated form. I also think that texting takes longer than a similar conversation in any other medium, unless it's a one-way, one sentence communication, It's just quicker to speak on the phone.
Email has completely replaced letters for me. Same effect, instant delivery. And I don't have to decipher grandma's arthritic handwriting anymore.