Electrickery, Physics (should that be 'Doesn't Work'?), Sums, 50% Harder Sums Free, and Stinks here.
Had a hard time at home (*handwaves*) from about halfway through, and discovered too late that I was a lot less good at sums than everyone (including me) had assumed, and that patchy teaching at a speed consistent with an extra AS's worth of workload was a terrible idea. Stinks didn't affect my university offers, so I stopped making an effort partway through; I never got the hang of Hexagons.
Losing the plot with Hard Sums does not prepare you for an Engineering degree. So I ended up doing Random Hacking And Sums That Only Go Up To 2 instead.
In real life, it's the Sums, lab skills and Things I Learned While Slacking Off that have been most useful. 'twas ever thus.