Adafruit DotStar Led's. Worked plenty well for us. They have arduino libraries on their website, and here's our roboRIO java driver for them:
link
To be honest, next year I'd like to use an arduino to drive them just to not soak up processor time on our main controller. However, having controlled from the RIO made it easy to tie the colors to different events on the robot (ex: ball in intake).
Other side note - a strand of 60 or so can soak up over 3 Amps at full brightness- more than some of the voltage regulator outputs can handle. Just something to plan for if you have tons of LED's.