But, muh lag!
If all of the above fails, it could just be general internet traffic in your area.
The more people trying to force send/receive data requests through your nearest exchange the slower things are going to become, in
some cases the following may help you, however this isn't guaranteed to work;
WTFast:
http://www.wtfast.com/
Battleping:
http://www.battleping.com/
Pingzapper :
http://pingzapper.com/
If these companies offer a 'server' try connecting to the 'Montreal' or Canada based servers (As this is where the NA/EU database centers are located for FFXIV:ARR). The rest are located in Japan.