For hot areas of the garden, succulents are a good choice like the sedum. There are plenty of low-growing varieties that look fantastic when paired with a few larger plants. Another really popular one is blue chalk sticks - senecio mandraliscae. Succulents also have the advantage of being able to be struck, so raid your friends and families' gardens.
A couple of other suggestions - Ajuga, also known as bugleweed, is from the mint family so is very easy to grow. And star jasmine is now being used as ground cover, not just as a climber. Mondo grass was also popular for a while but it's really my cup of tea. - greygardener
There are lots of grevillea varieties that are excellent ground cover for keeping weeds at bay as well as keeping your soil intact. They can look beautiful, too. - Isobel
I have tried a few different options. So far thyme has been the fastest growing and looks lovely. Here's a photo. - AndreaNg