I need it to grow fast, tall (6 ft), dense from ground up, ok to prune; and my parents also prefer a hardy plant, moderate water needs, wide (3-5 ft) and evergreen. I've done some research, but can't find one that fits most of the criteria. Please help. Thanks.

Here are my favorites:

From:
http://landscaping.about.com/od/hedgesfences/a/hedge_plants.htm

Boxwood
Privet
Yew

Here are a few evergreen ones (some are fragrant and/or have pretty flowers):
*Choisya ternata
*Carpenteria californica
*Grevillea
*Hebe
*Loropetalum

Have fun hunting for the perfect plant!