Best Trading system for the currency market

You mean best results ? or best place to invest ?

for the system have a look there http://www.swissquote.ch :)

Systems (if you mean trade signals, not the best broker) are always
very questionable ways to invest, Vegas LOVES peoople with "systems"
and so does Wall Street.

FOREX trading is a full-time business - if you want a relatively safe
way to invest in various currencies I recommend you look into simply
buying ETFs for the countries you think will be doing well - that
gives you the benefit of the economy doing well (or badly if you are
shorting) and the currency benefits. Few currencies go up if the
underlying economy isn't doing well.

You might want to look at EWC, EWW, EZA, EWL, EMM charts and others
just to get the idea.

Bloomberg.com has good information on currencies.

If you were asking which broker/investment management service is best,
that depends too much on individual needs, it depends on how often you
trade and how much you have to play with.