Honestly, my normal ping in netgames is 350 and more, I rarely get a 250 ping and never got a ping around 100. You're not alone, but I dealt with it, to justify my ping, it is because I live in Mozambique, which is in the South area of Africa a little to the eastern side, southeast of Africa to shorten it.
By the way, this may be sort of a head scratcher but, back when I used to play in netgames a lot, I kept getting 470 ping in servers that my ping usually oscilattes around 300-350 in days where the temperature is at 37 degrees or above. So my conclusion may be that heat also increases your ping, since I have a Super G Wireless Router, I assume it was overheating at that time as a rational explanation for higher ping? So if you have a router, I recommend not leaving it isolated in hot corners or anywhere else bound to concentrate heat, heck surrounded by many machines, not only that it may influence your ping, but your net as well.