The best functional programming to me, is the kind being integrated into various primarily procedural languages. I use it daily in C# at work, and find it invaluable in performing complex transformations on data. Python, C#, etc. have the best of both worlds --
the choice to use whatever is best for your situation.
I'll expand further, maybe to start an interesting conversation because I'm sure someone will disagree: purely- or mostly-functional languages are the original hype-driven languages. A lot of people say they're amazing, but don't actually do anything useful with them. Sure, some are making great apps with them, but they're clearly the exception. At the end of the day most of the people I've talked to who preach about how awesome their favorite functional language is have only gone skin-deep. Their experience is limited to the academic or experimental, and has never gone into the practical.
The few times I've tried to really master these languages, I've been left with no epiphanies. I've found it extremely useful for some problems, like data processing mentioned above. But for most everything else, it doesn't get me anything useful. On some level it is nice having the flow of immutability -- it "feels" right, like you've discovered something special. The same way adding an extra layer of abstraction on top of something might feel. But when I'd look back on it and ask myself what I gained from having it, there's really very little to be found. It is, mostly, a dogma.