Columbia Star Blackberry
I saw this new,still patent pending thornless,trailing Blackberry on berrygrape.org and is the only one that I could see listed as having outstanding flavor.Several are rated as excellent.I'm not sure if outstanding is better than excellent.It is probably subjective.
During a small search,the only place I could find selling the plant is lassencanyonnursery.com.The roots are sold out until 2015,but there are TC plugs and canes available.
I'd like to try them,but the 25 minimum are too many for me. Brady
Here is a photo of the plant,scroll down when getting there
Here is a link that might be useful: Blackberries for Oregon