I've always been a big fan of Fruity Loops. Back in 2005 I decided to buy the producer edition. One of the nicest things of FL is that you get lifetime free updates. Since 2005, I've gotton version 6 and version 7 with many new features.
I've bought allready a lot of software, but when it comes to quality/price ratio, I have to put FL on top of my list.
Now, there's great news: version 8 is announced and boy, are we in for a treat! Synth Maker will be included in FL !
Checkout
http://www.thefruittree.info/index.php/fl-studio-8-preview/ for more info.
Moon