Single best piece of suspension gear

What piece in your suspension has provided the best positive (negative?) change? New shocks/struts? Springs? control arms? Lets hear it! For reference, I am redoing my suspension on the 1st, and am planning on using KYB and Eibach primarily. Suggestions? I need front springs (mine were cut), struts/shocks, and rear control arms (hotchkis?). Peace. BTW, for you that have noticed, I'm new to this newsgroup and camaros in general, so I will try to post useful information when i know what im talking about.