Ableton Live V7. Get a cracked version from a torrent site. It's €400 new. And if you haven't got near-field monitors find some excellent headphones.
I like Reason, but it isn't simple to "dabble".
rig up a couple of Redrums
There's always Rebirth which gives you a 303, 808 and a 909 to mess about on, and is a free download