RetroUI Pro is more than its name suggests. Yes, it restores a Start Menu functionality, allows you to boot straight to desktop and disable hot corners. However, it also bridges the Windows 7 and Windows 8 styles, allowing you to display the taskbar and Start Menu even in the Metro Start Screen interface. Most interestingly, it allows users to run Metro apps in resized windowed mode, which means you can run them while keeping the desktop visible. On the downside, it's a paid app, but the functionality provided seems well worth it.
Verdict: RetroUI Pro restores the classic Windows Start Menu, but also adds some very interesting features of its own, such as taskbar view in the Start Screen and the ability to window newer Windows 8 apps.