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The Tamron SP AF 17-50mm f/2.8 XR Di II LD IF ($499) looks like optically good (sharp) lens, but it doesn't have IS (Image Stabilization), which is very meaningful in hand-held shots.
Another viable option is the Canon EF-S 18-55mm f/3.5-5.6 IS STM ($249). It is also an optically good (sharp) lens and it has IS. However the minimum aperture is only between f/3.5-5.6. It also has FTM (Full Time Manual Focus), which is very useful.
For low light video shooting, the Tamron 17-50 has an edge.
For hand-held video shooting where there is enough light, the Canon 18-55 STM has an edge.
The Canon EF-S 17-55mm f/2.8 IS USM ($829) has the benefits of both the above ones.
Camera bodies are being upgraded every so often, while really good lenses are lifetime investments. If you can wait a little and gather the money for the Canon EF-S 17-55mm f/2.8 IS USM, IMAHO it will serve you well.