While I read much less than I once did - I am delighted to have made some significant 'discoveries' both in fiction and non-fiction through 2015.
1. In fiction the main discovery was Jonathan Strange and Mr Norrell by Susanna Clarke (2004) which was certainly one of the best novels I have ever read - and within my favourite adult fantasy genre. I was put onto this by a BBC TV adaptation which was significantly flawed, but whose first two episodes conveyed enough of the novel's virtues to get me to read it.
2. The other discovery was another fantasy-genre writer Brandon Sanderson. This is very recent - I read the teen-fantasy The Rithmatist a few months ago
And just a few days ago finished a very long and extremely enjoyable audiobook version of the first version of a projected ten-volume adult fantasy called The Way of Kings.
Sanderson strikes me as an exceptionally deep and knowledgeable writer - he is also highly prolific and only about forty years old, which is particularly pleasing.
3. After many years of trying and failing to get onto his wavelength, the writing of Owen Barfield was unlocked for me by The Fellowship, a new group biography og The Inklings
Since then I have had great benefit from reading some of Barfield's philosophical books and individual essays.
4. Barfield was an Anthroposophist which again pointed me at Rudolf Steiner, which led to the discovery of Jeremy Naydler - a modern English writer on spiritual and philosophical themes who has particular expertise on Ancient Egypt. Convergently listening to an audiobook of teen-fantasy writer Rick Riordan's Ancient Egyptian Gods series The Kane Chronicles with the family (as in-car entertainment) led me to want to read more about Egypt.
5. I have also continued to read slowly, and reflect considerably upon, the writings of William Arkle - but strictly speaking, that was a 2014 discovery...