A couple general rules of thumb here:

- For younger and/or lower income people without kids, TFSAs tend to be better.  They pay little tax and receive few means-tested government benefits now, but will likely pay more tax and/or receive more means-tested benefits in the future

- For parents with children RRSPs tend to be better, especially with the new Canada Child Benefit.  The clawbacks on this can be pretty steep and there are often Provincial and/or municipal means-tested programs for parents as well

- For older workers and/or higher income people RRSPs tend to be better.  Older people tend to be close to the top of their earning range and pay a high rate of tax