Invoicing Sites – Best way to invoice clients?

Since we started our web development and web strategy company, LimeCuda, we have been trying out different ways of invoicing clients and doing accounting online. I have tried at least a dozen and am getting close to finding the perfect solution.

I decided to throw them out to you all and see if there are any you like particularly or ones I have missed. Suggestions?

I am leaning towards these first ones particularly.

As you can see this is a crowded space! I may end up doing a review post of all invoicing apps.