I use Morning Flight Gold Edition. It's a little better with offset than digital, but there were some recent upgrades that made digital more robust. They also recently added booklet estimating. It also does merchandise (for promotional products and brokered jobs, etc). The best part is the forum you can join and talk directly with the guy that wrote the program. There were two other programs I tried but one was unaffordable and the other had terrible english. So, I went with MF because it was easy to use and very affordable (translate- FREE). I have been using it for a year now and I can't imagine running my shop without it.
Morning Flight: Print Estimating Software for Offset and Digital
Keith