Well you're honest with yourself, and it seems like you know what the answer is. It's great that you're following a 'marriage-driven development' methodology, s

Well you're honest with yourself, and it seems like you know what the answer is. It's great that you're following a 'marriage-driven development' methodology, so pick a language and stick with it, be it PHP, Python or Ruby. None of them is universally better than the others. Most languages are better at solving specific types of problem. Choose what types of problem you most enjoy working on, and pick the language that suits those problems.