I use Cakewalk's Sonar Platinum, or rather Cakewalk by Bandlab now.

I use it because it does what I need. There are lots of good DAWs out there but not all of them offer the power and flexibility that Cakewalk provides. For me there were two areas that separated Cakewalk from its competitors: having a musical notation capability and instrument definition files.

For all I know, the industry favorite, Pro Tools, may have these capabilities, but I simply can't afford it. Cakewalk by Bandlab is now free (Sonar Platinum was about $400) and that's a price I can afford.

I like Studio One, but if I want musical notation, I have to buy Notion and use it as a rewire device. And I dunno if it does instrument definitions or not.

I also like Reaper, but I haven't played around with it as much. It has a nice musical notation interface. But I don't know if it does instrument definitions. Its price is sure right, though, and Reaper has a very active community.

Best,
Michael

My Music:
https://soundcloud.com/michaelmcbroom/albums