No difference than G. I highly doubt your internet connection is going past the speed of G (11mbp-54mbps depending on range).
The bandwidth of the N wireless signal doesn't help with gaming with you're not even using the maximum bandwidth of Wireless G.
What matters most is the ms delay between sending and receiving information to the router. Gaming routers use stronger signals to achieve a less than 10ms delay, but they are expensive. Using a wire is the only cheap effective way to get less than <1ms delay to the router.