Liz, there probably is no "best" program--each has own features, etc.
First you have to look at whether you have PC or Mac.
You should be able to get a decent PC program for @$30 US.
There may even be some free ones.

Just make sure you can make and receive gedcom files with whatever you use.

I use Roots Magic which used to be Family Origins--for PC --don't think they make for Macs
Its about $30