I want to move gutter drainwater underground away from the house. Do I need to lay solid pvc piping to a dry well or are there other alternatives? I am in the Northeast.

How far are you going and how large of a dry well will you dig? Some dry wells just aren't worth digging depending on size. Your grade must drop away from the home no matter what pipe you use. I use black plastic corregated pipe with no perforations until I am 30' away from the home and still maintaining a slope. You can dig you dry well there or do what I did, got a trencher and laid 200' of corregated pipe with holes and a cloth cover.