If you're just working in your basement or making basic recordings/mixings, go with Garageband. Need more features and aren't afraid of paying a bit more look at Logic Pro-X. I like LogicPro for composing music while ProTools is better for editing and mixing.
All of the above have a rich support for plugins.
Conversely you could select Audacity. Runs on windows/linux/mac and is pretty much free. It's a step up from Garageband, depending on exactly what you need to do. Definitely take a look at it.
One could pick their applications based on platform or based upon your requirements/needs of your work.
I chose the latter and went with a mac and LogicPro.
Btw, don't forget to to get good input hardware (mics, converters etc..). Believe it or not, that $30 cable that comes with the game Rocksmith does provide an ok USB interface, not quite as good as the equipment from Line6, but if you're just hacking in the basement for minimal cost, it'll work. With recordings crappy input = crappy output.
I would also spend some time on Homerecording.com browsing/searching their forums. This topic is covered quite a bit there.