I use Paperport.
In fact, I chose my scanner on the fact that Paperport was bundled with it. I had heard that it did a pretty good job and when I used to do more OCR scanning, it wasn't too bad, but I still had to VERY CAREFULLY proofread the file. The problem is, even a 90-95% success rate is a pain, if you have to fish for every deviation.
I'd advise checking some of the Internet review sites (hey, I wonder if tomshardware or anandtech have reviews on OCR software!!) to get some kind of feedback. I haven't looked into products here in a while.