Acrylic paint is basically liquid plastic. It comes in a wide range of gorgeous colours, is quick to dry and very durable. I use acrylic rather than oils for several reasons: ease of use (you can use water for thinning or clean up), colours (I like bright, strong colours) and are quick drying (I paint fast and like not having to wait).
Acrylic paint also can be used with a host of acrylic media that can do neat things like add texture or thicken or thin the paint so it can be built up or drizzled, mixed or crackled or all sorts of other fun uses.
I generally paint on cotton canvas though I occasionally also paint on masonite, furniture or even clothing.