I just finished reading The Love Hypothesis today and it was a quick and enjoyable read - enjoyed the fake dating trope, and the brooding, egotistical, but smart with a heart of gold love interest. He's got a Mr. Darcy-like ambiance around him - hot, smart, misunderstood. And she's a bit of a mess, but in a sweet and whip smart kind of way. It doesn't require a tonne of suspension of disbelief. 

I enjoyed how the main "conflict"

wasn't between the love interests, but within the protagonist and also within a believable scenario with an outside force,

that part was really well executed. 
I did not like the

unsafe sex between Adam and Olive and the sort of line about "being clean" and being on birth control, etc. It just seemed a bit hard to believe in this day and age to be both a scientist and so cavalier about something like that.