Reason to Love Rats #1: Compassion!

To many, rats are the epitome of filth and vice, especially compared to more positively portrayed mice. Look at their portrayals in media, such as "The Secret of NIMH," where the main villain is a rat in contrast to the heroic mouse protagonist, Ms. Brisby. Rabid, snarling rats are common enemies in tabletop RPGs (such as "Dungeons and Dragons" or "Warhammer") and video games ("The Elder Scrolls" come to mind).

The spawn of Hell itself.

Anyone who owns pet rats know they are anything but mean! Unlike pet mice who still act jittery around their owners even after being owned for a while, rats can develop loving bonds to their owners very quickly. Plus, it's been proven rats are one of the few animals outside of primates that have a sense of compassion!

Check out this study conducted by the University of Chicago.

This study conducted an experiment. Rats were placed in cages, but these cages were constructed so that they could figure out how to open them. The scientists found that most of the rats would help to free the other caged rats. 

So, there you go! Rats are genuinely loving animals, to their ratty brethren and in the case of domestic ones, their owners too. 

Special thanks to TV Tropes for their page on rats in fiction, "You Dirty Rat" and Inquisitr.com.