Temperature Sensor

What is the best and easiest to program sensor for arduino to detect temperature? Should I use LM335?

#define "the best"

what is the best for me might not be the best for you...

These five questions you need to answer for any sensor you ever want to use:
range?, (low .. high)
accuracy?, (repeatability of measurements?)
precision?, (how many digits?)
performance? (samples per time, blocking non blocking)
environment? (inside, outside, liquid, acid/base/neutral, ....)

tell about your project...