We carry many lines of nutrients, and all of them are amazing. However, a couple stand out in certain areas and I'd like to educate you a bit. CYCO has proven to be the best all around for big and healthy results. It's entire line has 100% pharmaceutical grade ingredients. I've seen more growers switch from their regular brand to CYCO than any other.
FoxFarm is an old favorite of dirt growers. It's full line including its powder finishers has one of the best results in the business. As far as the two big guys go, General Hydroponics (GH) and Botanicare, they both have their strong points. GH seems to be more affordable and user friendly for beginners. I personally use them all. I have used a piece of all of these lines for years now, and although they don't recommend it, cherry picking my favorites from each line has always given me top of the industry results.