I think a cryptocurrency with the lowest trading volume and users would be the fastest to transfer and most of altcoins don't have that much fees. And based on my experience IOTA, Ripple, Dash and Dogecoin have the fastest and cheapest transaction fees they all process transactions less than a minute. But Fastcoin claimed to have the fastest transaction processing time with 12 second but I've never try this cryptocurrency, check this https://bitcointalk.org/index.php?topic=218852.0 But personally It doesn't matter which coin is the fastest and cheapest to transfer, what matters is which coin have the potential to grow even more.