I would start off with Huzuni. It is easy to use, has a good number of features, and is free. Once you get a feel for that, try using WeepCraft. It has many more features, and is also a great client. If you don't mind spending money, Iridium is another good one for $10. Kinky also isn't bad, but it can be heavy on your Minecraft, so make sure you have a beefy computer. Note that some features such as fly are blocked by NoCheat, and it will kick you for flying eventually, on top of you moving around, but not getting anywhere. Nodus is terrible.
Reflex is the best by far, it even has a tweaking option. It is so OP, when you enable twerk, you will never die!
Nodus in my opinion is not very good but if u want a free client get huzuni. If u want a good,all around, balanced hack client and u dont mind spending $10, get iridium.
Nodus is terrible, you're right about that. Other than Iridium though, no client is really good for pvpfest. There are clients like Athena and Huzuni that may have good kill aura, but pvpfest allows admins to fly, so those clients are useless, as their fly hack is terrible. I would go with Iridium. If you don't want to fork out the $10, just ask a friend to send you the files.
Huzuni is a good hack client, otherwise get Iriduim as people above have said, if you don't mind spending $10
It's the only one I have used (except for nodus which I downloaded yesterday and ill remove today) Huzuni doesn't sound bad, ill probably try that