Looking at what others have requested I think that the best brokers to add to the existing FXCM is LMAX and Interactive Brokers. LMAX has very low spreads, typically 0.1-0.3 pips, many times lower. The commission is $5 (100k lot) round turn (about 0.5 pip). Compare that to many other Forex brokers and it is obvious that LMAX is very interesting. Interactive Brokers is a default choice since they offer not only Forex ($5 round turn commission) but many other assets like Futures and Stocks.

Dukascopy is also interesting but for traders with less than $50k it is not the best deal as the commissions are high.