I learn first Ai but one of my friend one day show me corel D, form that day i am fan of corel D, i think this is the best for designer. but sure for photo editing ps is the best .
@Jessica: I'm not sure with that. I using it for more than 4years. If you talk about ability; yes, Corel has a page, so you can make brochure, booklet or etc easily. also I have to admit that Corel has the easiest tool/way when you need to make shape or modify it. But when you talk about color I'm not sure. I still prefer Illustrator because its also to create mix media when you need polish your illustration in Photoshop . But in the end, the choice depend on the user.