Dreamspinner Press and Amazon have several best sellers on sale for $1. Many are the first book in a popular series. For $20 you can have a jumpstarter kit of male/male classics.
They are also on sale on Amazon for $1. The audiobook Whispersync deals that come with the purchases are incredible!
(The Amazon links below contain affiliate tags.)
Plan B is one of my favorite books of 2013.
An all-time classic and favorite of many, Shades of Gray by Brooke McKinley
If you have not read the Cut & Run series, you must start now! For $1, can't beat it!
Three books by Mary Calmes!
Fire and Water is is $2 on Amazon but $1 on DSP.