If you would have asked me this question 2 years ago my answer would have been completely different, since at that point i wouldnt have know the first thing about music theory and would have been just starting to do my grade 2!!
History - I love history - any form of history really!!
Practical - i love practical but because i put a lot of pressure onto myself to do my grade 8 too soon really i've kind of come to hating it in some ways cos instead of going in steps i just tried to do too much too soon, which, believe me, is NEVER good!!
Theory - a again too much too fast!! Grade 5 theory within one school term (about 3 months)!! Incredebly difficult especially since i'm totally thick as far as technical things go!!