First, fix your kitchen situation.

      So lets get straight to the point here, if you are going to cook, then you need to keep some items on hand. Building a pantry can be a bit over whelming and expensive! I find that I use a lot of the same ingredients over and over again. Here is  a list of what I keep on hand at all times, Ill add more later as I discover new favorites!
Feel free to leave me a comment of some of your favorites!

1. Olive oil! I use an extra virgin cold pressed moderate quality oil. Its interchangeable between high heat cooking and as a vinaigrette base. 
2. Sunflower oil. Also a great oil for both cooking and in a vinaigrette but with a milder flavor when compared to olive oil. I like to use this when I feel olive oil will be too overpowering. 
3. Sherry Vinegar. Adds a great and unexpected flavor to vinaigrettes and sauces!
4. Balsamic Vinegar. Great for both savory and sweet dishes!
5. Dijon Mustard. If you're only using this as a sandwich spread then you're seriously missing out. Awesome in vinaigrettes, marinades, sauces...and just about anything.
6. Lemons!!!!! I always have at least 6 lemons in my fridge at all times. I use them to liven up a dish or to make a great cocktail. The zest and juice are very versatile. I can never seem to have too many!
7. Soy Sauce or Shoyu. Its a great alternative to adding salt to a dish. You would be surprised how many uses this amazing sauce has aside from dipping tasty sushi into!
8. Mayonnaise. Not everyone's cup of tea but I find I go through a ton of this stuff! Making salad dressing, adding to marinade, or jazzing it up for a sandwich spread. If you're not fan, try to keep an open mind.
9. Chili garlic sauce. I love this stuff! Its great for adding a little or a lot of heat to just about anything and gives awesome flavor! 
10. Cinnamon. Not just for baking! I use this in all sorts of unexpected ways! From a main flavor component in my bolognese sauce to a great addition to marinades for beef and lamb!
11. Cumin, Coriander, Garlic salt, Chili powder. These are about all you need to make your own taco seasoning without the preservatives and ton of salt!
12. Agave, Honey and Maple syrup. All great alternatives to using sugar as a sweetener. I use these in savory and sweet dishes as well as a staple ingredient in most of my cocktails!