A good bulking supplement that you should try is ProLabs N-Large 2 I'm not sure if its the best but I think its good. Another supplement for bulking MILK.
N-Large2 has too much sugars in it for me (i think it is like 28g). Cyto Gainer by Champion has 56g protein and 84g of carbs. only 5g of the 84 are sugars.