My pick (Madison's) for my book boyfriend is James "Jem" Carstairs from The Infernal Devices series by Cassandra Clare.
Unlike most of Clare's fans I started with the Infernal Devices Series before the Mortal Instruments, and fell instantly in love with Jem from the beginning. Yes in love...Yes i know he isn't real but I do not care.
His mannerisms and some customs remind me of Darcy from Pride and Prejudice. He is loyal, honest, brave, artistic (he plays the violin...swoon!), handsome, courteous, and just amazing! He loves his parabatai, Will, like his flesh and blood brother and will do anything for him including losing something very important to him to make him happy (I can't say what....spoilers!!!). He cares deeply for Tessa and you can clearly tell this when you read The Infernal Devices.
If you haven't read them yet I highly recommend this series! I love it far more than the Mortal Instruments even though The Infernal Devices third book, The Clockwork Princess, caused a lot of feels for me....So my pick for one of Big Three is the amazing Jem Carstairs.