I'm thinking I will just play in response to d4 (and other non e4 moves) 1. ... e6 and if White plays 2. e4, then I will play a French.  If White plays 2. ... c4 I will look to play the Classical Dutch.

Right, time to redress the balance in favour of the Dutch:

1) After 1.d4 f5 2.Nc3 Nf6 3.Bg5 correct is 3...d5 where you can waste a tempo with Bf4 at some point or play the far more popular 4.Bxf6 exf6 5.e3 and the game will be slow and positional.

2)1.Nf3 f5 2.d3!? is interesting; I would play 2...Nc6 where Kindermann recommends 3.d4! and claims the tempo loss is less significant than the awkward knight positioning, although I am not so sure.

3) The Stonewall rocks .

I don't think 2.d3 it deserves (!) and certainly not ! Just because Magnus Carlsen thrashed a GM with it 8 years ago, does not mean that it is that brilliant, and whilst I agree it is a valid and good try for an advantage (which White should try for in any opening), I disagree that it is White's clear cut best - he has other good options.

Also, after 2...Nc6, databases actually prefer Black (only just looked this up), although of course this is by no means more than an indicator. There is definitely more to be discovered in this line.

You'll be glad to know I play f5 against d4 (half of the time, the other half I play Nimzo/Blumenfeld), against c4, and against Nf3 at the moment then!

Wow, none of those options work against Nf3. You may want to work on your openings a bit. 

1.Nf3 Nf6 2.c4 e6 3.g3 offers no nimzo (Bb4 is stupid here), no Blumenfeld (black is heading for Tarrasch or Hedgehog after c5), and 1.Nf6 f5 is almost losing by force. 

My take on it is:

The Stonewall isn't bad, but quite committing. If you play d5 without a real need you are stuck with that hole forever. It's tough to break, but not the most dynamic.

The classical/Ilyin Genevsky doesn't have this problem, but is kind of slow. Yes, e6 and d6 prevents any weaknesses, but white can play e4 before you know it. This means black can be stuck with an isolated centre pawn or a backwards pawn. 

The Leningrad is the most brutal and the fastest. You threaten e5 quickly, and if white goes d5 to stop you, you still have play on the queenside. A kingside attack isn't impossible, but it is trickier. It is also not easy to play and you need to make something of it with dynamic play, or you're certainly in trouble. I still like to (try to) play it though. 

What I meant was, against d4 I play the bracketed lot of openings, against c4 and Nf3 it's just f5.

Pfren showed me this game some time ago in a different thread- it's the source of black's problems with 1.Nf3 f5. 

There are of course other quite good lines than 4. Bxf6 exf6 5. e3. For example, I am quite interested in the continuation 4. f3, and many strong players such as Gelfand have played 4. e3.

@pellik - I already mentioned that game and ascribed it to why people overrate 2.d3. Thanks for posting it though.

@shepi - You're right, of course. I didn't want to list them all, it would take far too long.