Rats are awesome! I have TONS of videos on youtube of my 5 ratties (now deceased) doing tricks and other random, cute things :D They are definitely the best small pet to own. They're extremely intelligent and easy to train because they are so motivated by food. They also bond with you and are entertaining to watch.
The only bad thing about them (and why I refuse to get any more) is their respiratory and tumor issues. If you have the females spayed there's a smaller chance of tumors but the respiratory issues I've had with 3/5 rats, the other 2 died from mammary tumors. After spending hundreds of dollars at vet visits and for medications nothing worked, and I was forced to watch all my rats suffer as they died :( I would've had them humanely euthanized but my vet just kept trying to treat and make the most $ possible off me.