Depends on what you're looking for. The actual wrestling is probably better on SmackDown! (although, RAW's getting a little better, slowly but surely).
RAW has, at least IMO, the bigger names, and like johnnyc said, there's usually a lot more stuff going on, which can be good or bad, depending on how you look at it.
One thing I will say for RAW, at least last week, it focused a lot more on in-ring wrestling, instead of backstage stuff, and the upsets of Kennedy over Lashley and Carlito over Cena gave it more of an upredictable feeling than it's had lately.
And, if you want to waste an hour of your life that you'll never get back, there's always ECW!