Adobe
Pagemaker 6.5 and QuarkXpress 4.1 are the real big guns for DTP layout and both are supported on MAC/PC platforms and imagesetters.
I like the new bomber-- Adobe Indesign 1.5, interface is cool and can open QuarkX files. I'm learning it lately.
I use Photoshop, Corel and Painter on my logo/pix editing and design.
One good thing on QuarkXpress is you have to install once and a multi-OS rig can run it without re-installing.