I don't have a favorite because sadly, in 6 yrs of homeschooling, I have very rarely found anything I'd use again. I have changed their curriculum every single year, sometimes in the middle of the year if it was bombing badly enough. Probably the only constant has been the McGuffy readers, old school type readers that have been around for 150 yrs. I started using them in K and have used them off and on all the way through nearly jr high. They really suit my youngest who is just a no-frills kind of guy.