Recently I bought a rat and my roommate bought a hamster. We had just moved out of the dorms at ASU and were excited that our apartment allowed small pets. Also, I just wanted something to keep me company when my roommate was away and I hadn't had my own pet in a long time.
Although it was expensive to get all the equipment and necessities for the rat, it was worth it. Once she becomes less shy and more comfortable, I believe my rat will become the best pet (besides a cat or dog). And really, after all the initial expenses, she won't be that hard to keep up.
I already feel happier knowing that I'm a little less alone in the world. And it always feels good to pet something furry. Even WebMd agrees that pets have many health benefits:
1) Kids growing up with furry animals will be less prone to allergies and asthma.
2) They are great conversation starters and can possibly lead to dates (this is, of course, subjective).
3) Alzheimer's patients have fewer anxiety outbursts with pet companionship, and the elderly (and people of any age), in general can benefit from exercise and companionship with a pet around.
4) Playing with or petting a pet can relieve stress and possibly some depression.
5) People with AIDS can benefit from having less depression if they have a pet.
6) Having a pet can reduce your blood pressure in stressful situations.
7) After having a heart attack, those who have a pet may survive longer than those without one.
Here is the article from WebMD:
http://www.webmd.com/hypertension-high-blood-pressure/features/health-benefits-of-pets