The Art Gallery of South Australia is marvellous. There are multiple galleries and the collection is wonderful. I particularly visited recently to view the Venus Rodin exhibition which was breathtaking. There is so much to see, it will match anyone's taste. There's a café and a Gallery Shop with some wonderful items. Note though, there are stairs and various levels to navigate, so you may need to be mindful of this if you have accessibility concerns. Attendance is free for the gallery and there are paid tickets for special exhibitions. If you are a member of other State Galleries in Australia, your membership discounts will apply here too. It's a great place to visit.
The layout of this gallery is really nice in itself - the walk through from one section to the other is fascinating, especially as they vary each gallery by theme. There's a huge variety of different types of art from the first oil painting done in Australia to modern art and a good focus on Australian artists too.
They have some special galleries from time to time that can be good although often pricey.
Love the fact that they have a kids' section where kids can make their own art too.