Stand mixer-it depends...
If you like baking(cookies, cakes, muffins, mousse,etc), or making pastas/noodles, grinding meat, making sausages, it's very useful, it saves you time and effort; otherwise...
I've had one for 4 years, my wife likes it and uses it frequently, but I don't use it very often. I prefer making pastas with hands.
The one we've been using is KitchenAid, very reliable.