Depends what you trade as to where the best is. IG have double figures as high as 16+ for oil, for example whereas most have a fixed 6 pip spread.
Horses for courses but Capital Spreads is OK for me. But, I get a variable 1 - 4 pips with FXpro. usually just 2 pips and I'm not slipped on opens and closes, either. Of course FXPro is not spread bet...