I haven't tried Reaktor but that was my first instinct when I wanted to get some good software. I read a lot of reviews and ended up with Reason. The reviews for Reaktor generally stated that the learning curve was too steep and analytical for a lot of people. Reason got good reviews regarding the learning curve, but I find, after a year and a half that it is powerful yet limited. If I could do it again I would get something that was more complex and more open to technology, but also not so crazy. Which is why I purchased Cubase not too long ago. I'm still hesitant to really dive into it because I'm so comfortable with Reason, and having the new version of Reason coming out in a couple months may make it even more difficult to break away. What you start with may be what you end up staying with, so make the choice wisely. Get something you enjoy, but also something you'll have years to grow into.
Also, there are lots of odd programs out there that are not top-shelf names, but that do some very interesting things, if you're interested in being unique rather than making music on a grid.
Good luck!