Sociology and Religious Studies, I personally, would class as neither stimulating nor respected. I don't mean that to be snobby, but the majority of people I know who are doing Sociology and for whom it is their 'best' subject, well, they aren't all that bright.
Government and Politics, to me, seems like an interesting option. Indeed, at one point I considered taking it as an extra. I personally probably wouldn't consider taking it as one of my core ones because it is relatively new and hasn't really established any academic respectability. That said, and as others have pointed out, it is more respected than Sociology, RE etc.
Perhaps you should try for a mix? English Literature and History are by far my greatest subjects, and I am naturally good at these humanities/arts subjects, however, I have still taken the three sciences. I am not naturally as adept at them, but they do interest me, challenge me, and many top universities these days require a mix of decent academic subjects.
Perhaps you could try French? I never ever, for a second, thought about French for A-Level as it was never one of my favourite subjects and I didn't believe myself to be any good at it. Now however, I realise that a second language is a very useful skill to have, and that French compliments English and History perfectly. Geography? It bored me alot at GCSE level, but it seems to fit slightly with what you are taking, so perhaps you could also consider that. Also, don't dismiss the sciences, just because they are not your best; they do offer you are broader range of knowledge and skills.
Could I ask your GCSE predicted grades?
Good Luck.