I've done my own since high school. That said, I've paid to have them done a total of 3 times, including this year (2013 taxes). For DIY, I've done it many times by hand, and several times using TaxAct. This year, I was unsure about some aspects of dual-residency between 2 states, with wife full-time in LA & me with a 5 day a week residence in Texas & going home to wife on weekends. We have been filing jointly, but with each claiming to be a full-time residence in the respective states. I wasn't sure whether having purchased a house in Louisiana this past October would complicate things, with either Federal or State (LA). As a TX resident, I paid no state income taxes. Louisiana does have a state tax, so I was concerned LA might not agree that I was a TX resident. Also, when buying the house in Oct, we pulled $17000 from a Roth IRA. All from contributions, and I know what I BELIEVED the rules say, but I'd rather pay a pro to do the taxes than have to go through the hassle with the fed or state later on. Bottom line, I paid $256 to have taxes done & filed this time. I hated to hand over the $$, but in the end I feel better about it. Next time though, back to DIY.
BTW, as of January this year, I'm a full-time resident of Louisiana again. Was able to transfer from the TX office to the office in Shreveport. Now though, I've announced my 3 July retirement.