What zone are you in?
Any of the aloe varieties do really well in pots in full sun.
Lavender, petunias, tomatotes
I have luck with geraniums, marigolds and Gerbera daisies.
Any thing that likes full sun and will not mature too large for the pot will do well. I grow herbs in pots, too many critters run through my garden, and they do will and grow huge in ten to twelve inch pots. Most of the front and back yard are really shady and my veggie garden takes up almost half of the sunny area. I do grow tomatoes, leaf lettuce and peppers in pots on the side of my driveway that gets decent sun in really large pots, about 24 inches. One tomato per pot, two to three peppers per pot, six leaf lettuce per pot. During hot months I take the lettuce out of the hot afternoon sun and let them get morning and evening sun and they last until fall before the bolt. Any potted plant will dry out faster than plants that are planted in the ground, so you do have to make sure that they get watered often in the heat. When it is really hot, I end up watering my tomatoes two to three times a day.
Hi Valarie: If you are planting succulents, they are great for pots. If you are going to plant flowers, be sure to check the water every day, especially if they are going to be in the direct sun. Good luck