if you search the board there are a ton of threads on this topic :)
some of my favorites:
frozen fruit salad! - i always buy up a bunch of fresh fruit, chop it up, and freeze it before the burn. if you store it in ziplox and squeeze all the air out, you can just lay it flat in your freezer and it ends up very compact. it also helps keep your cooler cooler for longer ;)
bagged tuna steaks - you can find these right next to the canned tuna in the store. great for quick tasty protein, these are pre-spiced and dont need refrigerating..you can even take them out with you when you leave camp for a quick snack while you are out and about (dont forget to bring a fork ;) ).
chips and salsa - essential! a very social food, and salty and crunchy is good for the soul.
granola/trail mix - kind of obvious, but not to be left out, i make big batches of my own at home, measure them out into little single serving size lumps and wrap in foil. cheap and wonderful!
olives - salty and very energy-dense due to the high fat content.
good dark chocolate - perfection. this is the most wonderful thing to break out 5 days into your week to treat yourself.
tomato/veggie juice - the saltiness is so so good when you are running a little dehydrated, for some reason it just tastes like heaven out there!
coconut water - so hydrating and yummy (and very portable)! keep one by your bed so when you wake up hot as hell in your dome/tent/yurt/whatever you can chug one right when you rise. trust me :)
emergen-c, protein drinks - the harsh environment on the playa, along with the glee of adventuring, will deplete your body of important vitamins and minerals. i always keep emergen-c on hand to replenish electrolytes, and a good protein shake mix, like Alive or any non-denatured whey protein powder will do wonders for your energy levels.
when choosing foods, keep in mind that you wont want to do much preparation as the heat can be pretty exhausting and the city is one big distraction that will always be tugging at you. think plenty of portable foods, but don't go overboard with it. cooking just a couple nice meals can really make your week more enjoyable. our first year everything we brought was canned, dried, dehydrated, prepackaged, and we really missed real food!
hope this helps a bit! :)