There are numerous places near KSC where you'll get a great view of the launch, but I've never done this, so can't help with names or directions! I'm sure others here will be able to help with that.
However, if you want to see the launch without actually going over to view it, you can see an awful lot from most places in Orlando - you just have to know which direction to look in at the right time! I know this can't be nearly as exciting as being on hand at the launch site, but I've viewed two launches this way (one from Magic Kingdom and one from POR grounds) and they were still amazing experiences even from that distance.