Apple uses a website called Radar to let all users report bugs or to suggest new features. Alas, using the website is a bit of a mountain climb and many are put off by the time and effort involved.
However, if you want to help Apple make OS X better with the least amount of effort, you might try QuickRadar. This is a menu bar app that you can click to quickly fill-in details and submit them straight to Apple without a second thought.
When running the app for the first time you’ll need to click its menu bar icon, click Preferences, click the Apple Radar icon in the dialog box that appears, and enter your Apple ID username and password.
Subsequently, all you have to do is click the menu bar icon, then New Radar, and fill in the form. Alternatively, you can tap Ctrl+Option+Cmd+Space (Ctrl+Alt+Cmd+Space on some keyboards).