I use QuickBooks for my business.  It’s not a large business, really one person at the moment.  I played with earlier version of GnuCash but I can’t remember exactly why it didn’t suit me.

+ QuickBooks also allows automated downloading from banks like Quicken but I haven’t configured it like that.
+ Multi-currency support (it took years for them to implement this!)
+ Well accepted, my tax accountant knows it well and can ask me for information and tell me how to get it to her
+ Support via forums is ok

– This is not inexpensive software, I paid several hundred dollars for this and I update it every few years (like every 4-5 years).
– Even though I bought the software, they still charge for support (better to use their forums)
– They put out a new update each year which you have to pay to upgrade to, very few new features, mostly just a UI work over each year.
– They implement new features at a glacial pace.  It took them like 10 years to add the multi-currency support to the US version where the other versions (like UK and Canadian) had it.
– Probably the biggest negative for me is that QuickBooks is not really suited for a web hosting business or any business where you track customers with a monthly (or some periodic) payment like rental income.  It’s more suited for businesses selling parts.

A friend of mine suggested FreshBooks.  I have not yet tried it though.  It does not look like a replacement for QuickBooks, it seems like it would handle only the client billing part, something would still have to enter the bill into FreshBooks.

I use Quicken for my personal finances, its not free, there are other free options out there like GnuCash but I always seem to return to Quicken.

+ Quicken allows you to download directly from many different banks, so you don’t have to type in all those entries by hand
+ Links up with TurboTax (which I don’t use), but it’s easy for me to print out what I need for my taxes
+ Multiple accounts, many different types of accounts
+ Multi-currency support sort of.  Quicken will download stock prices but not currency prices.

– They come out with a new version each year which seems to include a UI work over and not much else
– They are glacially slow at implementing new feature requests in their support forum
– If you need support, you’ll be paying for it, even though you’ve paid for the software!
– Only downloads from US accounts (or the country where you bought it).
– No way to import an account other than typing in all those statements.  They used to allow importing QIF files but they say on their website that they changed their politique about this.