TurboTax Federal Free Edition
TurboTax is probably the best known and most popular tax filing application in America. Unfortunately, TurboTax recently suffered some bad PR when it was revealed that some fraudulent returns were filed using TurboTax. Even so, Intuit recently said that a spike in fraudulent state tax filings through TurboTax was not due to a breach of security. Intuit is also working with authorities to address the increase in fraudulent filings.
Although I do not personally use TurboTax, my opinion is that it remains a viable option for those who want to prepare their own returns. Intuit offers the Federal Free Edition of TurboTax for completing simple federal returns. Unlike some of the retail versions of TurboTax, the software runs in the cloud, so there's nothing to download. The Federal Free Edition does lack some of the features of commercial versions, such as the ability to import last year's return or to access IRS schedules A, C, D, or E. (Schedule B was not listed on the comparison sheet.)