Give it a go. If you don't like it, then you don't have to watch again, and if you do like it, well, you'll be glad you watched.
I like to think I'm a fairly liberal individual, and I enjoy it immensely - even the umpteenth time repeats. Seth McFarlane, who writes it and voices several of the characters, isn't afraid to speak out on a number of human rights issues and he often does it through 'Family Guy' and his two other main shows, 'American Dad' and 'The Cleveland Show'. 'Family Guy' also contains some cracking song and dance numbers, all voiced by McFarlane, who also happens to be an incredibly gifted singer.