Adam wrote an interesting post on must-have items for the kitchen. I found myself writing an epic comment, but thought better of it and posted it here.
I'm with him on most of his list, especially the silicone spatula. I've found the spoonulas to be essential for the continuous stirring involved in chocolate making. I buy 'em up when they're on sale whenever possible.
Microplane graters in at least two sizes. I'm always cheese-ing something up with mine. Recently, I gave in and bought a coarse grater because it came with the plastic cover. My ancient fine grater still has the cardboard safety cover.
A good mixer. I just bought a KitchenAid stand mixer on sale at Amazon.com (you can read about it at my site).
Le Creuset grill pan. It's perfect for grilling fish and pork chops (says John).
You said a pepper grinder -- I also use a salt grinder for the big chunks of sea salt.
Global utility knives. They're ideal for cutting all manner of food, especially veggies.
Nexcare waterproof bandages by 3M. They blow BandAids away.
Oxo salad spinner for all the obvious reasons. I also use it for drying other veggies.
Mixing bowls in a variety of materials: glass, steel, plastic, etc. Some foods react to certain materials, and some hold heat/cold longer than others.
Lock n' Lock storage containers. These are the best containers I've ever used. They keep food fresher longer and seal air/water tight. Even better than Tupperware.
Shelves for cookbooks.
Ziplock freezer bags and Sharpie permanent markers. This way, you can write the date on things you're freezing, and it won't disappear or rub off.
Silicone tongs. We use them with the grill pan as well as the All-Clad cookware (even if it isn't non-stick).
Electric tea kettle. It boils water in a fraction of the time it takes on the stove.
Cushioned mat and kitchen clogs (I have a Williams-Sonoma mat and Dansko clogs) for long periods of time on your feet in front of the stove/counter. They really make a huge difference.
Kiehl's Creme de Corps for your hands after cleaning up. This lotion is very good at rehydrating skin. You won't need to reapply it before you go to sleep, either.
Good music and a reliable CD player nearby.
A garbage can that opens with a foot pedal.
I could write an even longer list of food items, but here are my top 10 (not in any particular order and preferably organic):
1. Butter (nice, considering I'm a former vegan)
2. Horseradish (my not-a-secret-anymore ingredient in so many recipes)
3. Garlic (fresh and jarred)
4. At least 10 different spices (pepper, oregano, basil, thyme, rosemary, cinnamon, nutmeg, paprika, mustard, and ginger to start)
5. Eggs (preferably from cage-free birds)
6. Fresh baby spinach
7. Oats or oatmeal
8. Some sort of sweetener (I'm agave nectar-friendly at present)
9. Club soda or seltzer
10. Lemons (they always seem to make so many things zippier)