Citra and cascade are my favorites. Simcoe is one that I don't agree with the hype. Simcoe gets way too catty for me. I really prefer citra for the flavor additions(opposed to bittering) but cascade fits the bill for any addition. Magnum is great for clean bittering.
Centennial. I've got a love hate thing going on with Citra. I find that it falls off the cliff really early, and when it does it becomes absolutely undrinkable