Unfortunately that's impossible to answer. It's like asking: what's the best car for the best price?
You need to first establish a budget... that will help us rule out a lot of options right away. If your budget is too low to get you into a respectable solution, then we'll let you know! We also need to know your tank dimensions and what types of coral you want to grow. Do you have a preference on the type of lighting source... T5, LED, MH, a mixture?