For some reason, this makes me think of a Buddy Cop show.
"One of them is a loose cannon detective that plays by her own rules. The other is a straitlaced patrolmare that always does things by the book. When Sergeant Celestia makes them partners, will these two ponies be able to drive out Discord's crime ring, or will they just drive themselves crazy!? Find out on Twilight Sparkle & Applejack: Canterlot Cops!"
I especially like what you did with Twi, though the tail seems a little too anime. It'd probably look better with her standing, though. Perspective can throw it off. -and- While AJ is at fifth place on my little list, she has qualities to be admired. And no other pony would look that good with a ponytail. (Or two, at that)