I found very much to enjoy in Alison Weir's bio of Isabella, but as Anerje says, she does play favourites with her subjects. It annoyed me how many things she left out that she thought would reflect badly on Isabella. For example, saying that 3 of Hugh Despenser's daughters 'became nuns' is hardly honest, given that Isa forcibly veiled them 5 weeks after their father's execution. Or saying that Isa's income from Jan 1327 (which Weir has Ed III granting her, although he was only 14 - obviously she granted it to herself!) made her 'one of the great landowners of the realm' when in fact it was a third of the annual royal revenue and the highest income that anyone in England (kings excepted) received in the entire Middle Ages.
I really love Plantagenet England too. Extremely readable. thorough, scholarly but entertaining.
"Sans lui n'estoit rien fait, et par lui estoit tous fait, et le creoit li rois plus que tout le monde." Without him nothing is done and through him everything is done, and the king trusts him more than any other: Hugh Despenser the Younger and Edward II