I'm toying with buying one of these super sexy vita mix or blendtec machines which seem to "replace up to 9 accessories" but cost about $500 (yikes)
I certainly love my blender, but it's a little gutless, and I run between it and my immersion blender all the time-not to mention the food processor and juicer which rarely get used due to heinous cleaning pain afterwards.
I must admit to being overly involved with my George Forman grill which was a real game changer in that it does just about everything my bbq did but inside and NOT in the rain.
Then, of course, the purist in me says that that big chef's knife I bought replaces all that other stuff.
What about you? What appliance/accessory MUST you have in the kitchen.