Campaign Cartographer is a CAD engine that has been repurposed to provide mapping functionality. It also has many style packs in the form of its annuals and huge numbers of symbols via its symbol packs. Some folks find the learning curve steep, but there are many video tutorials and training materials available.

If you have some drawing skills and are expecting to make your maps from scratch, go with Photoshop (or GIMP)!! I believe they can produce superior results, though I have't used Campaign Cartographer but I've seen many maps on these forums. I use an older version of photoshop with XP-Pen Artist 12 Pro drawing tablet with screen and I love it! I find that most of the stunning maps on these forums are made with Photoshop, GIMP or a program like that.