As many said bittrex Will be great for the Paragon. Bittrex has the trust of a lot of investors and its one of the best exchanges. Its a good opportunity if Paragon get listed on bittrex, but live listed and others exchanges is a good thing too, much people can exchange paragoncoin and its important for the liquidity. Its also important for the visibility but for that point the team manage that very well and i think ico will have a lot of investors !
Usually ICOs got to bitterx to be listed, but it would be better if PARAGON is in some others as well, livecoin, cryptopia, hitbtc, kraken, now if it manages to get into poloniex, that would be great, poloniex doesn't include coins easily, they have big standards, so much that they kind of stopped accepting new coins, so, for now, bittrex, livecoin, cryptopia and hitbtc are good choices, but definitely not only one, we need diversification, having only one exchange will make the token easy to manipulate (dump, pump, bits etc.), so is necessary to have at least 3 excahnges.
Poloniex is not doing good lately, very slow support, very slow withdrawals, it added bch only after 14 days. HitBTC is chinese if I recall correctly