Zinnias are my favorite annuals. I have bred them off-and-on, mostly inadvertently (without any specific goal), for years. Some years I keep 0 seeds and just start over. There are tons of varieties and they're easy and fun. I'm currently growing them indoors and plan to plant lots outside later this spring.
That said, I also have a soft spot for marigolds--the regular French/African kind--and they are also my favorite annual. The smell of a crushed marigold leaf takes me back to childhood in a microsecond. And the flowers with such deep, rich, shades or burgundy, orange, and cinnamon make me want to wear them in my hair and chant Hare Krishna all day long. They go well in bouquets (some years I do a marigolds-only arrangement of different colors) and they are extremely easy to grow despite their long and thin delicate-looking seeds. A guy I used to date bought me some seeds as a present one year and even though we're no longer together, I still grow them.
That said, poppies are also my favorite annual. I love the breadseed (opium) poppies for their seeds (I'm fat and I love the eastern European poppyseed rolls). Their glaucous leaves speak to me for reasons I have never understood. I love the ephemeral and impermanent blooms of the double Shirley poppies--they tease the viewer with the utmost refined grace and delicacy, and then POOF they're gone until next year. I love the hardiness and eye-shocking color of the Icelandic poppies.
That said, Tithonias are also my favorite annual. I first encountered these as an adult when I was living in a really hot part of the country. An old abandoned church with a razor wire fence had them growing all along the side of the fence. The plants would reach eight feet tall and each year I would collect seeds not being quite sure what they were. The shade of orange is HARSH and in-your-face in a way that few other oranges are (the common daylily comes close). They are good for arranging in mixed bouquets and they are extremely easy to grow.
That said, sweet peas are also my favorite annual. When I lived in the south I could not grow them because it got too hot too soon. Here in PA it stays cool long enough into the summer that I can have blooms until June or July. The fragrance takes me back to old Victorian Europe (or what I have read about in novels). They are also extremely pretty--something they don't get a lot of credit for. I find their shape to be somewhat reminiscent of orchids.
That said, pansies/violas/heartsease are also my favorite annual. I love the vast array of forms and sizes and colors that they come in and I also love the way they smell--FUN FACT ALERT--these flowers produce a chemical in their fragrance which means that after you smell them, you can't smell any other flowers for certain amount of time. They do this to "paralyze" your nose and keep you from going to other flowers. That's how they're pollinated. They also taste delicious and look super gourmet floating on a bowl of soup.
That said, cosmos is also my favorite annual. When I lived in Kentucky these used to grow wild in an old exposed "smoking area" on a derelict building in the inner city of Louisville. They were bright, bushy, and profuse with their blooms at least until November every single year. And they reseeded themselves. The goldfinches loved them. I think of cosmos (of any color or size) as roughly analogous to poppies in the way you can arrange them--very carefully, and for short periods of time because they are delicate--but cosmos have a MUCH longer bloom time than poppies.
That said, I also love nasturtiums very much, particularly the small, bushy, varieties, and the varieties with mottled leaf patterns. I don't usually like variegation in plants but there's something about the big, round, lilypad-looking variegated leaves of the old-fashioned "Alaska" variety that really makes me smile. The leaves are delicious on a sandwich with tomato, mayonnaise, and cheese. The flowers are edible, too, but I always find them so pretty. These guys grow in super poor soil--in fact, rich soil will produce fewer flowers. And, their seeds are weird-looking. Every year I study them very closely even though I've seen them many times before. They're a fun flower.
That said, I also love portulaca (moss rose). I grow these every year, as well. Sometimes if I let a flower pot dry out and it's 5,000ยบ outside, these are the only things still living. Their leaves are semi-succulent so they actually prefer dry, hot, conditions. Their flowers open and close each day so they can look "raggedy" after they're done but the seed pods are extremely tiny little bowls full of seeds open for the wind (or birds) to disperse. I think their seed caps are under-rated.
That said, OMG I'm late for work.
