Let's make this clear: you shouldn't just go to Drupalcamp London 2016 this March: you should always go to Drupalcamp London, every year. I've been going for three years now (this will be my fourth) and they're invariably worth the cheap entry fee: earlybird tickets (£40) have sold out now, but the standard ticket for two days, including lunch, is just shy of £50 and absolutely worth it.
This year I'm also planning to go to the pre-conference CxO day, a slightly more business-y day for executive officers, business owners, higher management and the like. It'll be great to get a bird's eye view of both my own business and the wider industry, to inform my future direction (wherever that might be!) I'm not sure if they'll all take kindly to a Chief Gardening Officer, but I live in hope.