Hoya HMC filters (multicoated) are excellent and not really expensive. The two lenses you mentioned are both 52mm filter size, I believe -- I know the 28mm is. I recommend orange as a good black and white filter -- and don't forget a polarizing filter, since it's great for cutting haze and really bringing out the clouds. (Yes, it's not just for color.)

Just saw the post above -- $20 for three Nikon filters is a really good deal.