Mostly BA - made my first redemption with them recently too (RFS),
Had my first ever try on U2 a go a week or so back - didn't really like it, and one segment on BE (as the BA timings & routings were naff).
Would like to try some of the other OW airlines - JAL and CX, but haven't a reason to yet.
LH have put me off with their service changes last year and the same for the LX LHR-GVA route too.
SK haven't enticed me to visit somewhere new.
Have been meaning to try A3, but yet to see an enticing destination/fare whilst avoiding potential public strikes.
The only real draw for *A is SQ and given the routes from LHR, I don't fly them every week.
If BA give me good service over the year and I find myself with a chance to renew Gold, then I might stick with them another year...or head over to *A on A3 and mostly SQ.