Great additions to your list include a whisk, high-temp-resistant rubber spatulas (le creuset's are the cutest), two wooden spoons (olive wood is nice)—one oval, one flat-ended for scraping the bottom of the pot, an angled sauce spoon, a hand-held strainer called a spider, and a slotted fish spatula with a knifelike blade. A collection of nesting metal bowls is essential (metal because one can then pinch-hit over a pot as a double boiler). I use strainers instead of colanders because they can double as flour sifters. Oh, and a microplane grater, and a good quality peeler. I'm not yet a big fan of ceramic knives, but ceramic peelers are heaven—much sharper than metal ones and no more inextricable rust. And no tool will make you a more confident cook than a thermometer (I'm generally a minimalist, but I love mine, which like this one has a portable receiver that updates me on the progress of a roast). A small salad spinner is nice to have, too (you do wash those pre-bagged salads, don't you?).

A mandoline is superhandy, giving the impression of better knife skills than you may have. The inexpensive Japanese kind is great for cucumbers, onions, and fruit, although if you make a lot of French fries or potato gratins, you should go for the more expensive, sturdier French kind, which can handle the stickiness of the potato starch.

And a not entirely necessary but wonderful tool is a food mill, which makes great mashed potatoes, and is wonderful at grinding tomatoes (and deseeding them for sauce) and pureeing soups. You can get away with a blender and a strainer, though, for most of its functions (except the mashers).

One final note: Kitchenware stores have a fondness for selling fondue sets, butter warmers, pastry torches, and their ilk, but unless you melt cheese once a week, you don't need to bring these fire-y things into your kitchens.