I'd love Horses, Generations and Romance content - in that order.
I don't care for the type of pack as long as EA makes a sensible decision.
I'd take a baby stuff pack for instance if the were planning to enhance babys with a patch. I'd take Horses as a GamePack or as an EP paired with unicorns and fairies. I'd take a funeral stuff pack as long as it's not the only Generations based pack. I'd take a wedding stuff pack as long as we'll be getting more Romance interactions and a chemistry system at a different point.