What is the best seismic attribute to eliminate multiples from seismic ?

What?? It is extremely difficult at a post-stack level to eliminate multiples, maybe some deconvolution algorithm can help you out  but I don't think so. In a post-stack level is almost impossible to get rid of multiples. In a Pre-Stack level you can easily see the multiples in the CDP gathers (nmo corrected), and then you can attenuate them using some radon filter or, the stack itself can destroy some multiples. Before that you can use some predictive deconvolution test on the common offsets or shot gathers. In conclusion, at a pre-stack level a smart radon filter can help a little with multiples, especially for AVO analysis.