Lots and lots of Zinnias! Big ones, little ones, medium too.
I am also using quite a few petunias in pots. That's the only way I can keep them from running rampant. I also use a shrub called Mussaenda( which blooms ALL summer long) and Mexican Petunias or Ruellias for summer long color. Of course all my shady areas are always Impatiens. And sunny spots get Cannas, Bananas, Bloodflower, Stawberry Gomphrenia, and lots of little groundcovers like Blue Daze, Coreopsis, and Fan Flowers.

Torenia for color in shade. Tried it last year and loved it. Someone gave me a packet of cosmos seeds and coleus seeds, so if they sprout I'm going to try those this year too. I have a big asparagus fern that I overwinter in the kitchen every year. It's going back out to its spot in the big stone container as soon as the tulips finish blooming. Haven't decided what to surround it with this year. And last is annual salvia. I've had such poor results with perennial salvia and such good results with annual salvia, the I'll put a bunch of white salvia in the scent garden again this year. It makes a great filler while I'm waiting for the permanent plants to fill in.

hanging baskets: fuschia, portulaca, ivy. (the ivy's really the centerpiece. i change out the other stuff.)

annual color: Petunia Hurrah red with orange marigolds:) sounds like too much but looks pretty good in front of Joseph's coat rose! oh, and always zinnia, sunflower, morning glory.

I tend to rely on foliage and easy houseplants for hanging baskets. "Wandering Jew", mixed with a shiney plain leaf pepperomia is a great combination. I keep cuttings rooted in water all winter. I also use these in the deck pots. This year I am adding creeping orange zinnias to "match" (well, it does in my world) the purple stripes of the "wandering jew". I don't really like to buy annuals, so this works for me.

GGG