I have to say for being a fast food joint, their salads are really fresh! I've ordered their side salad and their full size salad with grilled chicken and haven't been disappointed yet by their freshness!
I've tried the salad at a nearby competitor and I've had mixed luck. Some days the red hair girl gives me a decently fresh salad, but most of the times you can see the vegetables are starting to wilt. That's not the case at Jack in the Box. When comparing the side salads you definitely get more from JITB and I prefer their ranch dressing, although the competitor do have baked potatoes.
I sometimes pair the salad with a value menu item like the chicken sandwich or Jr. Jack.
This is the place I go to for salads when I want it fast.