Two of the things I love the most are conversion design and client communications. One of my favorite parts of design is the ability to present actual data that influences my design decisions.
Diving deep in the mind of the customer through their buying process. Starting with a soft sale quality content driven model and even moving into a hard sale remarketing and landing page approach.
Enjoyment is an understatement when it comes to creating wireframes and watching the project mature into a full blown conversion machine.