Personally I like Farouk Chi curling irons, as also the flat irons because they get REALLY hot. When you have long hair (I do too) drugstore brand curling irons will not do the trick, they do not get nearly as hot as salon irons and I have the same problem - my hair never curls. It is a bit more pricey but if you want your hair to curl - its worth it
I personally think BIG curling irons work better for long hair because when they are smaller its hard to fit all your hair on them..