If you're looking for "best" the answer isn't "scanner". But the best of the pile of crap after the testing I've done appears to be the BCD436HP but not with the stock antenna and not while in motion. Hope that helps.
Now if you had about $3,000 to spend then your best performer would be a Motorola APX portable. And don't drink the Kool Aid, you CAN program a Motorola radio without it affiliating and it works fine. I use 4 Motorola radios programmed that way daily and have yet to transmit or have ANY reception issues, and I live in an area with several LSM systems. I even did a comparison video in Youtube. Search here for the thread titled Best Scanner for Philadelphia.