Well, depends on what you'll be needing it for. UBOT and iMacros are geared towards internet based stuff. WA is more of a Windows client, like the old batch scripts, only more advanced.
But why don't you try iMacros firts, if you don't want to shell out $200 just for the fun of it. It can do pretty much what uBot does, except the if/else/then statements, which are pretty cool, but depending on what your background is and what you need to do, you can do without them.
So, basically, if you're going to create simple bots like account creators, then iMacros is your best choice. (I've personally done several acc creators in less than an hour with it)
BUT if you'd like to create more complicated bots like, then you should take a look at uBot. But, be warned, the fact that you don't need to know programming doesn't mean you won't need to spend hours of learning and trying to figure things out.
uBot has lots of features and it takes time to learn to use them properly. Other than that, it's an incredible tool.
