don't know what's been posted so far..
I definitely recommend trying blends first and see what suits your taste.
Italian seasoning blend or Herbes de provence -- Both very good blends for pastas and salads and to spice up instant food and side dishes.
Basil -- Almost everything tastes great with fresh basil. It goes great with roasted tomatoes, cheeses, pasta dishes, ground up it makes an amazing sandwich spread with some olive oil, salt, and pepper.. this herb is so versatile.
Chinese 5 spice -- It's popping with flavor and some spice.
Lemon pepper -- Really cheap, and blends well with almost anything.
Cilantro and lime -- these two were made for each other, they're very cheap, and they add a great flavor to rices, mexican dishes, soups, etc.
Cumin -- too much is a bad thing, but it is a really earthy sort of spice that enhances saucy dishes quite well and compliments savory-sweet things too.
Chervil, tarragon, parsley, and paprika -- Throw a bit of these four spices into any breaded dishes you're making to give them waaay more flavor. I'll bet my boots on those four spices being in KFC's chicken recipe.
Also, this isn't a spice.. but this combo almost always makes an awesome sauce:
- A bit of oil, garlic and onion sauteed until onion is soft
- Add mushrooms, let them absorb the oil
- Sear meat in pan until brown on both sides, transfer to baking dish
- Add wine to medium-high heat pan and use spatula to scrape off all the 'stuff' that stuck to the pan and pour it on top of the meat
- Bake until cooked. Serve over veggies or carbs.
Also, if you're lazy or indecisive, there are two things I highly recommend:
It's a sort-of-cheap way to try a variety of spices and see what you like or don't like.
Marinades. They're only about $1 each on the cheaper side of things, and you can marinate almost anything in the fridge all day and cook it in the evening as usual. (Lemon marinades on salmon fillets are absolutely amazing.) They also tend to have a ton of salt and spices in them already, so if you like a particular recipe you can always look up what gave it the flavor.