Me personally, I brainstorm in Photoshop with fonts, however, for actually application I design in Illustrator. Or sometimes, all in Illustrator. Many times you'll want to create your own fonts or use quality manipulations on a selected font. Far to often is the case that designers depend solely on created fonts for titles. It shows lack of ability (if you've been in it for awhile). One of my personal favorites are the anti-bush tees I did awhile back: