The Lymond series is superb, I think Lymond is much more engaging than Niccolo, the main character from her other series. The level of detail is fantastic, though the quotes in medieval French and Latin leave me cold, they do emphasise what the educated person used then.

Have you read King Hereafter? Possibly my favourite of her books, but the last two Lymonds are also contenders...it's so tricky when there are so many good books to choose from!