These files are all system images for the Android emulator. That is, they contain the filesystems for the emulated Android phone inside the emulator. The ones that are in SDK directories can be removed from the Android SDK Manager and reinstalled any time you want.
The ones in your user directory were generated by running the emulator: they contain the files and data you've created in the emulator. Only you know whether they contain any important data. If your emulated Android system doesn't have any data you want to save, you can delete them. Make sure to remove the corresponding AVD entries that use them from the AVD manager, as the AVD won't be able to boot once you've removed its files: you'll have to start a new AVD from scratch.
BTW, it's not necessary to download a fresh Android SDK each time you install an IDE. Just tell the IDE the path where you installed the Android SDK. Rather than just worrying about the large files, it'll be better to completely remove the copies of the SDK you're not using.