Hint...It goes unnoticed.
I think the best UX goes unnoticed. Not to say that it doesn't leave a mark though. I think it marries a unique taste for creative flare (aligned with the brand) to form and function. While I may have some bias to what I (or we) design, ultimately it's a team effort that should be data driven. If we can meet internal business requirements and have positive user feedback, then I think we have a solid foundation for future iterations to build upon.