I can ping that IP too, was just pointing out that not all IPs will respond - so unless your are SURE it will and should, its not always a valid test..
So your traceroute is sending traffic for that IP out to your isp and internet.
Do a sniff on your wan and validate you send out the syn on 80 to get to their site, or ping etc.. If that is the case then its not pfsense issue at all and something on your isp, the internet between your isp and that site, or the site themselves blocking your IP..
How many other sites can you not get to- are they all in the same netblock?