Scanning Antenna

[RadioGuy3007]

What is a good out door scanning antenna? I currently have the following antenna pictured below on the left. Its hooked up to my Uniden BCD996T and I want to replace it with something better.

 

[SpectreOZ]

Better?...as in better for any particular segment of the bands?

Additionally if you could get your existing antenna above surrounding obstructions (ie. that tree) you'd likely notice an immediate improvement for minimal time/outlay...