The last game I paid money for?
Trine... Because I wished to bolster my library of games accessible to my laptop. I paid for the access to this game via the steam sale, and as such I do not count this game as purchased, because I do not own it nor is it considered my property.
Purchase - That which is obtained or acquired; property; possession; acquisition. (I will stop pointing this out when people stop touting steam as some divine benevolent benefactor)
The last game I purchased?
It is a three way tie between halo 3, Midnight Club: Los Angeles, and Dance Central, all of which I paid 7$ for respectively and all Purchases were to help rebolster my aging 360 lineup. (My god I love pawn shops!)