IRS Tax e-Filing Experiences?

jdrogers asks: "Last year I e-filed for the first time and it was by far the worst tax experience of my life. It was expensive. It was often hard to interpret the meaning of the 'easy questions' designed to determine my tax status and I found that the questions often led me to answer incorrectly. Two of my three state and federal returns were sent back to me due to errors. This year, there are many options for cheap or free e-filing. How have other Slashdot readers fared and which websites offer the best filing experience? What did you love or hate about it? And most importantly, which one should I use this year?"