I choose not to immunise my children. I have researched all I can, and am happy with the result.
Most of my reasons have already been discussed here. I beleive there is no place for mercury and formaldehyde in my childrens bodies.
Whilst having measles or chicken pox may be uncomfortable, I don't think it is worth the risk. These are simply normal childhood illnesses. Yes there are some extreme cases, but that is with everything.

How many of the live vaccinations are grown on monkeys internal organs? This isn't propaganda, the was a massive report on the Age recently - it certainly shooshed up the people who were on my back to change my mind. It's funny that these same people have done no research themselves...

Every single child I have known that has recently had chicken pox have all been vaccinated against it.
The term "immunised" insinuates that the child has immunity from disease and this just isn't true.
Having said all this making an informed choice - which ever way you decide is the only way to go.