My dog won't always come when called. I enjoy seeing him chase rabbits, should I stop him from doing this?

If you can't call him back from a rabbit then I would not allow this to continue. If your dog doesn't always respond to the recall, I'd suggest you back up your training. The more he ignores you calling him, the less important the recall becomes. You want to build more value for coming back to you than whatever he's interested in whether it's rabbits, sniffing, birds,people, other dogs, etc..

There aren't any shortcuts to this and it's the most important command for any dog. I have a dog that loves to chase rabbits as well, I don't allow it because chasing animals is a self reinforcing behavior. Even if they never catch one, it's an instinctual behavior that is fun for the dog. The more you let him practice that, the stronger the behavior will be and the harder it will be to maintain a consistent recall.