I've actually had very good luck with the Preventic Tick collar. I've found ticks crawling on my girl with that when I used to use it exclusively, but I never found one attached. That was not true when I was using Frontline. They aren't a good option if you have dogs that bite each other's neck.
From what I'm hearing on the boards, response to Frontline is regional, some places it seems to work better than others. Some believe that the Frontline Top Spot is more effective than the Frontline Plus. I think that was my experience.