Family Guy has been awful since it's reincarnation for Series 4.
There's definately a demand for Seth MacFarland's type of humour, but for me it's become too diluted in painfully outdated pop culture and internet meme references, long musical segments, way too many cutback scenes, and lazy writing.
Seasons 2 to 3 on DVD, or American Dad to a lesser extent, are evidence of MacFarland's better work.