Brian - FIL's name, I like it but it sounds dated.
William, NN Will - Really like it
Felix - NMS, but works great for other people
Adam - Like it
Nathaniel, NN Nate - Love it
James, NN Jamie - Good solid name, I agree with pp that Jamie is used more as a girls name these days, but I think it still works for boys.
Tristan - NMS
Stephen - Like, but I prefer Steven