Personally, I'm not a fan of garlic salt or powder...it's really simple to keep a head of garlic around, and break of a clove as needed. Call me a snob, but I like to have ingredients that are as close to their natural state as possible.
I'd recommend buying fresh basil, tying it up at the end, and letting it hang upside down (over your sink is a good spot). It'll dry out. Whenever you need basil, just take a few leaves and crumple them up in your hand. The taste is FAR better than the stuff already in jars.
For salt, use kosher salt - it enhances the taste of food without making it taste like "salt". Buy a small pepper mill and fill it with whole peppercorns. Grind away when you need pepper. Again, when something has already been chopped up at the factory, it's months old by the time it gets to you, and the essential oils have all evaporated.
Penzey's Spices are great! Very high quality. You can order online at
www.penzeys.com
Other than that, I'd recommend having the following on hand:
Essentials:
Basil (dried as above)
Cinnamon
Oregano (can be dried as above. Really, any herb can.)
Peppercorns
Kosher salt
Chili powder
Head of garlic
Olive Oil
Nice to have:
Chive
Cayenne
Cilantro
Dill (the weed is more useful than the seed)
Paprika
Rosemary
Lawry's Season Salt
Also, I always try to keep a few lemons or limes around. Lemon is especially versatile! If that's not practical, buy a bottle of Real Lemon juice.