I've found out that you can only move apps and games to the SD card if you root the phone (so even those apps that supposedly move them do not work) and that is not something I'm prepared to do on a new contract phone I've just got.
@Darren You should be able to install most things to SD card, not sure if there's a way to default to that but if you go into settings and look at an application there should (in many cases) be an option to move it to SD card. This doesn't apply to all apps and I think in a lot of cases some files are still left on the phone, but a lot of it can be put on SD.
@Mr-Brett - The S3 has around 11 GB of usable space free on its internal memory but it soon goes once you've downloaded a few of the Gameloft 1 GB+ games.
What is especially annoying me at the moment is that I cannot download Real Racing 2, a game I bought a few weeks ago, as it halts at 97% every time, regardless of whether I have 1.2 GB or even 2.2 GB free. The installer claims the game is 800 MB in size yet when I exit it, once it gets stuck at 97%, I find that I have just a few KB of memory left! I have no idea how large this game actually is and how much memory it needs but it appears to be over 2 GB. Has anyone got this game installed on their S3? I'd appreciate it if you could tell me how much space it actually requires please. Thanks.
PS3, PS4, PS Vita, Wii U, Xbox One, PC (Intel Core i7-4770K, 16 GB, 4 GB EVGA NVIDIA GeForce GTX 980 SC, Windows 8.1 Pro), 128 GB iPad Air 2, 128 GB iPad mini with Retina Display.