I'd personally say Sonar (Only because I'm STILL having Emagic withdrawals, and have never been a huge Steinberg fan). But I would also recommend FL Studio. It has definitely grown up over the years, and has a lot of features (especially Rap, Dance, etc. oriented), that none of the big packages feature (or they do, just not as intuitively). And has a lot of live performance oriented features. And it can ReWire with Reason, act as VSTi, in other programs if you upgrade later, and it's only $150.
Try downloading some demos.