I am currently reading a biography of Isaac Newton, but the thing that makes it really fun is that it was written by a friend, a colleague here at New St. Andrews. Mitch Stokes is our math and philosophy guy, or, as they say in the biz, fellow. Peter Leithart has written a bio of Jane Austen in the same series.
Here is info on the book, and of course they let you buy more than one. Or try Amazon.