I have used many. My fav has got to be whey isolate by myprotein. Gaspari do some good products. N-Large is not the best so I would look at trying something new... but hey if it works for you then great.
I usually just look for an isolate. Whey concentate (amongst many others) is in most mixes. Although it has more health benefits due to being in a more natural state but everything else is better when it has gone through the next level of processing. Whey concentrate is cheaper but can give me bloat but I am fine with all others.
My current one is a mixture of all but I love it. It has everything in it. I get no bloat or discomfort. That was a surprise considering it has approx 65g protein, 65g carbs, 4.5g creatine, 2.5 arginine, 11.5g glutamine, 17g BCAA's etc etc. It's called Anabolic Mass 2 by Garnell nutrition.
I would try trueprotein but I live in the UK so myprotein is my choice for most things.
I plan to get their weightgainer (used it before) and stay on that for many months along with a great diet. It has 4 ingredients... scottish oats, barley, whey isolate and milk isolate.