Probably the Canon EF-S 55-250mm f/4.0-5.6 IS is a lens I would retain for a very very long time.

The lens is extremely light weight and portable, has a reasonably wide focal length, can take sharp images and is highly versatile - can be used for variety of themes - wildlife (with some limitations) as well as others.

And last but not the least at below 10k, its a steal!