I might be in the minority, but I've learned to love the challenge of taming a beast of a code base.
Coming in and helping out people who don't have *anything* in place and slowly adding order has a satisfaction level all of its own.
Building out a test suite as we document business logic and then planning a refactoring can be rewarding too!
The most exciting phrase to hear in science, the one that heralds new discoveries, is not "Eureka!" (I found it!) but "That's funny ..." -- Isaac Asimov