A TIP120 (121, 122) bjt darlington is ok for a short piece of LED strip. Up to 60 LEDs or so.
And if you don't mind them being a bit dimmer.
A TIPxxx can drive a longer strip, but will get hot and needs a heatsink.
If you're serious about your LED strip, then use logic level mosfets.
TIP120: emitter to ground, collector to LED strip negative, 220ohm resistor between base and Arduino pin.
Mosfet is almost the same.
Source to ground, drain to LED strip negative, 220ohm resistor between base and Arduino pin.
Wise to also add a 10k resistor from Arduino pin to ground, to stop the mosfet from turning on when the Arduino is still booting.
Leo..