Suggestion for ND Filter for beginner

I have a Canon 7D + Sigma 17-55mm 2.8 + 70-200 mm f4. I am intermediate and would love to get a ND Filter for blurry/smooth water effects and to slow down my shutter spead. what would all of you suggest? I am looking at spending up to $200. I know that isn't a lot but I'm not a professional photographer, this is just my hobby/obsession!!

I just recently got into using ND filters myself and I bought a 6 and 10 stop B+W filter (77MM) and bought Fotodiox step-up rings to use them with my non-77MM glass. ND's obviously serve their purpose and take some getting used to, especially 10 stop that requires focusing with the filter off.

I'm a huge fan of B+W filters, personal preference. I know a lot of folks get the Lee system but it's not cheap. It is really versatile having the square/rectangular glass filters tho. I know others who use Helipan filters with success.

Where you'll get into a lot of conversation/debate is whether you should go full ND or graduated, and if graduated do you go hard or soft. For me I started with full NDs to get my feet wet and I'll expand as I develop my taste on what I want to use them for.

If you're not doing landscapes with horizons, you very well can get by with full NDs. But I know folks who use grads for situations other than horizons. There's no easy answer to your question, I can only speak on what I went with and I've personally had good success with my B+W's.

I'll try to post some samples later.

Edit: BTW, B+W filters aren't the cheapest of the bunch either. My 10 stop was $150 I believe, 6 stop was close to that as well. But you have to keep in mind you're putting glass in front of good glass, don't go for the cheap stuff, which given you're $200 budget doesn't sound like you were planning to.

Maybe look into a Variable ND? This will let you dial in how much ND you would need for certain situations. There's a lot of pros and cons of using a variable vs a fixed ND, but it may be a good way to figure out what you need, then invest in a certain stop.

I use Hoya HMC ND filters. They are a solid option, the only downside being they are a little more difficult to clean than B+W. But they are cheaper and good performers.

I don't like variable ND filters for long exposures outdoors. My experience with these is that the polarizers introduce some color weirdness and uneven exposure if the sky is in the frame and the filter is being used for high attenuation (like as a 0.9). They are more usable IMO for using wide apertures at max shutter speed. But I don't use them at all, only regular ND filters. With the variables, you always have to be aware of the polarizer side effects (e.g. killing reflections from flat surfaces, etc)