IMO, there's probably no better test than a craigslist or DrudgeReport redesign. At my workplace, we're hiring a new web designer (mostly Photoshop work), and the test that we put her through was a Photoshop redesign of the home page of craigslist.

Very popular and recognizable, yet so universally hated by many designers for being outdated in style and technology.

Anyways, she past the test and now we're hiring her!