TurboTax, I like to know there is a free version out there as well, that I could use if I really needed to. It is the easiest way to file your taxes, and this is coming from a former tax accountant. Don't pay hundreds of dollars if you just have a couple of W-2's and/or interest income, mortgage interest, charitable deductions, etc. TurboTax walks you through every step and doesn't miss a beat.
Another plus? Should you need help, you can live chat with someone immediately. It's a great program and super frugal way to get your taxes done! They'll also file your federal return for free, and you can either mail in your state return for a few dollars or pay $27.99 to have TurboTax e-file it for you. I myself think it's worth it to make a trip to the post office to save $20, but I say do whatever is easiest for you!