I do the IB... and from hardest to easiest it's... Biology SL... too much stuff to remember and a bad teacher Classics SL.... some of the texts are just really boring and it's hard to motivate myself to read them Maths Studies... I just have no interest in maths anymore, and my teacher's bad Latin HL... I don't like the grammar, but we get a dictionary in the translation paper and I like the literature bit Philosophy HL... I really love Philosophy so it seems easier to me English HL... Not that bad.
SL biology sucks ass. It seems HL always get the good teachers in sciences?
1. Chemistry. I am not cut out for quantitative chem. 2. English language. I got it, I just can't memorise everyone's names and theories ad nauseam. Dropped it at AS. 3. Biology. Not really hard. 4. English literature. Piss. Easy.
Geography-Lots of vague questions and a lot of various terms to remember, and lots of graph shapes etc to remember Biology-Not too difficult but a fair amount of precision required. History- A lot of information but easy to understand and link things together. Chemistry- Personally find it easy to understand and all that's required is knowing a few equations.