Band-in-a-Box

Pros: Thousands of instruments played by experts and literally thousands of music styles to choose from. Put in your chord progression, choose a style and a band arrangement from the thousands of choices and in a moment you have a professional rendition of your song.
Change individual instruments and make easy arrangement adjustments to refine your song or, if you like plug in a guitar or keyboard and add a great lead track, and before long you have it all ready to make the final mix, there is no end to how creative this programme is.
Now, record your vocals on another track, add harmonies using BIAB's inbuilt harmony creator and then mix it down or transfer it to RealBand, BIAB's built in DAW, to add some more creative touches and then produce amazing sounding mixes.
I used to own a recording studio in Sydney Australia right beside the Sydney Harbour Bridge and the Sydney Opera House and it had thousands of dollars worth of great gear but, seriously, I can make better tracks in my lounge room with this programme, a couple of good plugins (Limiter, DeEsser, Reverb etc) for RealBand and a couple of decent mikes.

Cons: What didn't I like?
I have used BIAB for about ten years now and about the only criticism I have is that, in the latest version, the little window that allows you to perform Chord Settings, doesn't close when you click OK. You have to actually click the close X in the top right hand side to close it.
Apart from that, nothing.

Overall: Like I said, I have been using it for a long time and I am still continually amazed at its ability to create great sounding tracks. The longer you use it the more you seem to get out of it so it is an ongoing delight.
It blows me away that i can produce great tracks with a computer and just a small suitcase full of peripheral gear.
If your ambition is to produce some music, any genre, believe me, this is the best friend you can have. I absolutely recommend it.