Having been running FreeBSD on laptops since ~2004-2005, I've had the best luck out of Dell laptops. ThinkPads are a close second, but ACPI is wonky on mine, resulting in being able to sleep but not wake up. Fun times when I need to be mobile. :)
As with most things FreeBSD, you'll have better luck not running current generation of hardware, but the previous generation, as support for the newest hardware usually lags a bit.
As with most things FreeBSD, you'll have better luck not running current generation of hardware, but the previous generation, as support for the newest hardware usually lags a bit.