I like UI design. You wouldn't know it from reading this blog because I've rarely talked about it but it is one of my passions. Good UI design is pleasing to the user, simple and easy to use and most of all intuitive. You can become a better UI designer by researching good patterns, studying good and bad interface designs and practicing your skills.
Years ago I used to give a presentation called “User Interface Bloopers - How not to create a UI” that cataloged dozens of of silly dialog messages, awful form layouts, bad UI metaphors and pathetic error messages. I still have students send me examples of bad UI in applications they are using.
Want to learn more? Read Jan Miksovsky blog. He's had plenty of practice creating UI's including work on Microsoft Vista and Microsoft Money. There are some great tips on his blog.