Avoiding !important is generally very good advice, although the ZOMG NEVAH! approach is a bit overzealous IMHO.

One good example would be overriding random external styling (e.g. an included CSS file some plugin you use). If their stylesheet has very long and specific selectors, you can either repeat them entirely (#plugin .container .subcontainer .input-wrapper.input-wrapper-blue input[type=text]:first-child) or stay within your general selector-writing practices and use !important instead. I'd argue the latter is a better practice.