Filters - ND Grad and so on. Lee, Coklin or another?

Hi,

I'm looking for some advice on which filters to get.

Generally the lenses I am interested in using are 77mm filter type.

I wanted to get some ND grads, perhaps a hard and soft, and a few other effects around the 1,2 & 3 stop range.

Which of Lee or Cokin are the best value and will one suit the other holder?

Are there other brands I have not considered? Any other recommendations?

Thanks!