It's YouTube's birthday. Q: How old do you think they are? A: 5. Yes. Just five. We reckon we've spent at least three of those years on YouTube and if it wasn't for the tears we've shed in laughter at their billions of hours of footage, we'd really hate their success right now. You can't watch all the videos on YouTube (more than 10 hours of footage are uploaded every minute) so here are the best bits of the last five years.