I'm not a fan of his stand up.
I'm not a fan of the Office or Extras. They're okay, but I never wanted to re-watch them.
I do like Derek. I had no idea he could act so well.
I am a fan of his XFM stuff (and subsequent podcasts, audio books, and TV show) with Steven Merchant and the epic Karl Pilkington. I've heard/seen them all, many times, and they never, ever get boring. I can't say I've ever experienced that anywhere else.
I find his laugh completely infectious, while others find it nauseating.