I was always scared off from cooking Thai curries myself because of the quantity and rarity of ingredients involved (how many grocery stores stock galangal?). I've tried a few different store bought sauces, but none of them could compare to the restaurant sauces in terms of spice level and overall flavor.
Then I discovered Thai Kitchen's curry pastes - these cute little 4-inch jars that contain all of those unusual, but amazing Thai chiles and herbs that make curries taste delicious, smashed into a flavorful paste. They come in green and red (sadly there's no yellow), and both are delicious. Each one comes with a recipe on the jar, which just involves mixing the paste with a few ingredients which are readily available in the Asian food section of any major grocery store: fish sauce, coconut milk, canned bamboo shoots, and brown sugar.
Add some cooked chicken or shrimp, some veggies if you like, and steamed rice and you've got an amazing meal. The veggies that pair best with the curries are sliced red or green peppers, cooked onions, peas, and zucchini.
The nice part about making curry this way is that it's simple, but you can adjust the spice/sweet/salt level yourself to make it taste perfect. If it's too salty/spicy, add a little more brown sugar or coconut milk. If it needs more salt/tang, add some more fish sauce. If it needs more heat, add more of the curry paste.
To add extra flavor or flair, I also recommend adding some chopped cilantro at the end, or some Thai basil (which I love, but have a really hard time finding). I also think it's worth the extra step to serve it with Jasmine rice versus plain old Uncle Ben's. So yummy!