Dont push him into anything, just show him gameplay videos of great exclusives like GOW3 and Uncharted 2; if he wants, he will buy, if he doesnt, thats cool too.
I myself will be very piss off if somebody keep on pushing some product very hard, that I may lost interest in the product at all and purposely buy the competitor product, or refrain from buying just to piss him off.
Everybody has their own preference, and especially for fanboys, logics dont work here, compare product features is pointless, we ourselves dont know why we prefer something over the other. Try and explain the beautiful graphics of a PSP to a child playing Pokemon on a DS, or explain a powerful 12megapixels Android smartphone to someone waiting in line for Iphone 4.











