Tecknet MD12 has been good and cheap. Having fairly small hands I picked up a Jelly Comb MV009, which is even better with softer touch buttons and they do larger alternatives with the same basic design. Either of these makes the much more expensive Magic Mouse feel pretty hopeless in terms of comfort and they glide across the surface more smoothly.
Beware of so called ergonomic alternatives where the shape it too vertical and looks like a shark fin. They can force the hand into an unnatural position.
I have a Wacom as well, but this is reserved for photo retouching and that sort of thing. I find the pen a bit awkward for web design work.
N.B You don’t need to spend a fortune to find a good mouse, but it will probably take you an hour or two of use before you know whether something is right for you. Whatever you choose will feel a bit strange at first.