I like Outright. They try to sell you on their paid version to make tax time easier, but I find it's not difficult to get all the info you need for taxes from the free version.
I can't imagine entering data into a spreadsheet after every sale like Crochetgal does--that would require a degree of discipline that I don't possess. lol
The only information I track on a daily basis is: the dollar value of all items listed that day, and the dollar value of all items sold (totals across all four shops). Of course, I do also record all my supply purchases, but that's not a daily thing.