I've used a few over the years - QuickTax, Ufile, and StudioTax (free). They pretty much do the same job. I think QuickTax (now TurboTax) and Ufile are very easy to use. Both have online and software versions. So there are lots of choices out there.
And you got to love Netfile. Within 10-14 days the refund is in the account.
RainbowsMist, I haven't heard of Tax Chopper. I'll have to check it out. I'm suprised some of these free versions are still out there. I've seen a few over the years get bought out by the big guys.