My staples: All the Whey Protein, NOW, RPN , NutraPlanets Bulk , and BCAAs (typically a staple, unless Im strapped for cash and I use ).
Regarding weight gainers, purchase a quality protein powder, and then make your own high calorie shakes. Use natural ingredients (protein, pb, yogurt, fruit, oats, or what ever you like) and use that. Commercial gainers are over priced and lesser quality imho.
As far as supplements to aid in lifting, what are your current goals?