If you must use plugins with WP Themes, TGM em’

Occasionally, it pays to include plugins within themes. This is not to say you should EVER bundle the plugin with your themes, but you shouldn’t. Use TGM plugin instead which will advise customers what plugins are required for your theme to work.

This is a excerpt from George Stephanis talk at WP TV link is : George Stephanis: The Seven Deadly Theming Sins .