As a general rule, I'd take anything that wasn't an airline based in the USA.
Does your *A FFP have reciprocity with VS? If so, it's hard to beat VS Upper Class from either JFK/EWR to LHR.
If not, I would use Swiss -- for example, JFK-GVA/ZRH and then connect to a LCY or LHR hopper, but then I'm a big Swiss fan. Direct, your choices are CO from EWR or US from PHL, but US is pretty 'eh'.