This question has got to rank in the top ten and the answer is simple, the one you feel comfortable with. I have personally tried and used several different kinds of genealogy software in the past and have settled on one or two that I now use all the time.
One of the best programs for beginners is Personal Ancestral File or PAF from the Latter-day Saints, you can find it here. And best of all, it's free. Another one, and the one I currently use is Legacy. It is also free and is very easy for new comers.
Another one is Family Tree Maker which is available from most stores that sells software. The price differs depending on the package. More information can be found on their web site, here.
Some other software packages are,
| Generations | by Sierra Software |
| Kindred Konections | |
| Ancestral Quest | |
| Family Origins | |
| Family Gathering | |
| Ultimate Family Tree |