In the warm weather, I'm big on salads, not necessarily those that are all greens, though.
One of my favorites is made with cous cous, which you can buy in bulk (it's cheaper than buying the little boxes of it). You make the cous cous and then add a tiny bit of oil and vinegar, lemon juice, raisins, chickpeas, a tasty green like arugula (chopped) and some red onion. It's quick and tasty and has always been a hit at family gatherings. You can eat it warm or cold. You can sub out the raisins for other dried fruit such as cranberries.
Quinoa can also be used as a base for warm and cold salads. It's awesome with different fruits and veggies mixed together. You can flavor it in many ways. And quinoa is a really good source of protein. Plus, it just tastes really good.
Pasta salads are also on my list of warm-weather food. You can make any kind of dressing you want and load it up with whatever veggies you have on hand. I often use broccoli, carrots, red onions, green beans and peas in mine. I also add olives and Daiya shreds for a little tang. My favorite dressing is Italian, which I also make myself because I really can't stomach a lot of the jarred stuff. I just think it's nasty for the most part. Homemade dressing is wicked easy to make. If you have a Betty Crocker cookbook, there are several you could make for pasta salad.
ETA: Oh, and grilled anything is so good in the summer, even fruit. Grilled pineapple is delicious.