1. "That will never work."
2. "... That said, the labor laws make it difficult for us to do a lot of the suggestions [you] put out. And we do live in a lawsuit oriented society.""
3. "Can you show me some research that demonstrates that this will work?"
4. "Well, if you had some real-world experience, then you would understand."
5. "I don't think our customers will go for that, and without them we'd never be able to afford to try this."
6. "It's fantastic, but the salesforce won't like it."
7. "The salesforce is willing to give it a try, but [major retailer] won't stock it."
8. "There are government regulations and this won't be permitted."
9. "Well, this might work for other people, but I think we'll stick with what we've got."
10. "We'll let someone else prove it works... it won't take long to catch up."
11. "Our team doesn't have the technical chops to do this."
12. "Maybe in the next budget cycle."
13. "We need to finish this initiative first."
14. "It's been done before."
15. "It's never been done before."
16. "We'll get back to you on this."
17. "We're already doing it."

All quotes actually overheard, or read on blogs/comments about actual good ideas.