If, like me, you like using CSS3 to make the buttons and gradients you may find this useful.
One of these links you will probably know about but in case not check out colorzilla.com. This is an excellent tool for creating them and it also includes legacy browser support.
I use a Mac and I spotted a desktop App called CSS3 button builder which is very easy to use but at the time of writing doesn’t include the legacy browser support.
The third, bestcssbuttongenerator.com , is nice because on the left panel are recent and popular examples. Clicking on any of them will load it into the main window and when you click on the button you get all the code. Legacy browsers are also supported.