I have never had a pet until I got married. I know what you might think, but don't get the wrong impression.

Read forward!

Some 4 months after I got married, I bought my wife a guinea pig, as a birthday present. It was either this, or a hamster, but hamsters are a bit too small, and I read that they are much more prone to biting people.
Not being around animals that much, I was quite amazed how smart these little beings can be. In a couple of days it has mastered drinking from its bottle, but not only that. We take it out daily, and put it on the couch, using it as a playground. To prevent any "accidents" staining it, we use a double sheet. In the first 2-3 days, "accidents" occured quite a bit.
However, with only a bit of encouragement (read treats), it learned to use a box to wee and poo, and all this training took under 15 minutes. Now we just keep on reinforcing what it has learned. Inside the box, is another matter. It can make quite a bit of mess, but we can't stay around her all the while to teach her the proper way to behave. We're just happy we can play with her without the fear of having our clothes and furnishing stained.

We play, and it chirps and begs (squeals) for treats. It does so at this very moment, and it is very cute.

I'll add a picture of the little gal.
So, question comes, do you have/had any pets? What impressed you most about them?