After practising my best "revise for one day before the exam - except for RS and other equally crap subjects" technique I managed the following:
A* in Maths (taken in the January)
A* in Physics
A* in Chemistry (still a mystery to me)
A in Biology
A in German
A in English Language
A in IT
B in English Literature (what a terrible subject

)
B in DT: Resistant Materials
C in RS
C in Geography (missed a quarter of the exam out - in all the mocks we did, we only did three questions - one each from sections A, B and C. In the real exam we had to do two from section A).
As others have said, it's just a springboard to A-levels, then A-levels to Uni, then Uni to a decent job.
Am currently at the Uni stage after doing 4 A-Levels, and getting:
A in Mathematics
B in Computer Science
B in Physics
B in Economics
(I knew instinctively which subjects would be fun)...
For all its foibles, school is one of the best times of your life so savour it.