Cignal for me (yes, I'm a Sky HD subscriber). I prefer Cignal because they have surround sound encoded programming for certain HD channels, while Skycable HD only has 2 channel audio. We use Cignal HD in the office, and it's been quite reliable so far (I guess it depends on the location and the dish installation/aim).
As for programming, Cignal has Food Network HD and StarWorld HD, while Sky has Fox Crime HD. Price is almost the same, with Cignal being cheaper by about 108 pesos per month for a similar channel lineup. Cignal had waived the receiver and installation fee for HD subscribers (aside from an initial lease fee of 1290), versus Sky's 5000 peso charge for the HD box, plus installation charge (I don't know if they've changed the prices though).
However, if you're after an extensive SD Channel lineup, then Sky would have you covered (Gold + Platinum packs).