Despite my total inability to shop in TK Maxx, I recently discovered that they are quite good for kitchen stuff. My mum had taken me out for the day and made me go in there. They have a lot of rubbish but they also have some really good pots and pans as well knives. Worth checking out, the prices can be pretty good compared to other shops.
I would also echo Trouser's suggestion of a big wooden chopping board, handy for garlic bread, pizzas etc as well as for cutting veg when you've got a lot of it to do. You can usually buy sets of three different sizes which is useful.
A knife set in a wooden block can be really handy as it contains different types of knives as well as a really easy (and safe!) way to store them but it's not worth it if you don't spend money on it. I have two in my kitchen (I'm not even really sure where I got them) but I never use any of the knives except for one which is for cutting bread-the set is just to cheap and as a result the knives are rubbish.
I got an excellent set of knives for my birthday one year which I use all the time, it came with a sharpener and has five different knives.
One great big pot with a lid is really handy to have for making soups, stews, basically any easy one pot meals.
This sort of grill pan is great for cooking steaks and finishing off chicken with skin on. That link is meant for illustrative purposes only though and not a recommendation of a particular one.
A wok is a great choice as well since stir frys are really quick and easy meals after work. Easy to clean as well if you haven't coated it in stuff while cooking you can just give it a wipe with some kitchen roll and oil.
Most gadgets can be left until you know what sort of cook you are and what sort of stuff you are going to be cooking. No point in buying something only to find you never have a use for it but if you find yourself wishing you could make your own bread then it's easy enough to go out and get a breadmaker.
Get a good roasting dish as well that you can use for making any sort of roast meat as well as doing roast veg which is an easy and lovely side for any meal. I like making med style veg (like you can buy in supermarkets.) Plus it is good for doing garlic roast potatoes (yum yum).