If you like the 50mm focal length and have the budget, the 50/1.4 would be a better choice.
Having said that, the 50/1.8 is a good choice if you want to get a feel for fast primes (and 50mm) cheaply.
Some info about the 50/1.8:
What's good?
- It's light.
- It's small.
- It's fast (as in wide aperture).
- It's sharp.
- It's inexpensive.
- On an APS-C camera, it provides classic portrait framing.
What's bad?
- Its barrel and mount is plastic.
- It has no distance gauge.
- It has no ultrasonic focus motor.
- It's slow to focus, and noisy, too.
- The focus ring is awkwardly positioned and small.
- It has a five-bladed diaphragm, producing unappealing pentagonal bokeh.