The drawbacks to the American NEMA 5-15 plug are that it is still a shock hazard as the pins aren't sheathed with insulating material. Also, the pins get bent easily and are a bit undersized for 15A in my opinion.
This was in Las Vegas and the cheap- and flimsy-looking plug sockets just struck me as a funny counterpoint to the unhinged level of excess that was on display everywhere else.
Also chances are the sparking isn't due to the way the plug is inserted in the socket. It's more likely due to the fact you have connected a capacitive load such as a computer power supply, and the fact the the mating parts of the receptacle are very close to the front making a spark more visible.
I just looked at the plug on my mac book air, it's identical and goes in easily either way around. It sparked when I unplugged it and plugged it back in again, both ways :)
Sparking will happen regardless of the way you insert the plug into the socket. This is probably due to a lack of inrush current limiting in the notebook power supply. When you plug it in, the discharged capacitors appear as a short across the AC line momentarily as they charge up. This is what causes the sparking.