You can always add a different mix of veggies, but don't forget that there are some simple ways to pep up the dressing.
Before you add the goodies to the bowl, throw a spoonful of Dijon mustard in. (If you can find tarragon Dijon, it's great for salads!) Then you basically add a splash of vinegar. You can use white wine, red wine, rice wine vinegar, lemon juice, lime juice, or orange juice for different flavors. Then drizzle in some EVOO. For a creamier salad dressing, crack an egg yolk in there. Experiment with fresh herbs like tarragon, chives, basil, etc.
Or you can start with 4-6 anchovies, mash them up with a fork, add some chopped fresh garlic, S&P, and juice from 1/2 a lemon. Add a dash of Worcestershire. Crack an egg yolk in, and drizzle EVOO for a tasty Caesar dressing.
I've also found some really tasty flavored EVOOs (Persian lime infused, blood orange).
I always add leftover salmon, broccoli, cauliflower, asparagus, whatever, right into the salad, too.