I just can't decide which one I want to buy
Do yourself a favor and don't get the 4GB variant. As for the XBOX 360 series, I would go for the Xbox 360 E, simply because it's the newest of them. If you chose, I would buy the 360 Slim (IF YOU DON'T HAVE 4GB).
Thank you very much
I would still be interested in what advantages it has
I mean the E
I don't think there are any big differences, EXCEPT for hard drive capacity.
So more memory?
Yes, as I said, there are Xbox 360 versions that only have 4gb memory, which I would NOT buy at all.