Roses, and pretty much only roses as my favorite. If you drop a rose in a pool of water while it’s raining, it’s such a cool effect... they also have more meaning behind them. They can mean life or death depending on the rose.
Also, RWBY, the Anime from the state I live in (Texas), main character for the show is Ruby Rose, so it’s obvious that Roses are superior now.
I love sunflowers! They're bright and tall and look generally like the flower equivalent of hope.
Cacti probably don't count as flowers but they're my favorites too.
i love peonies, tulips, sunflowers and hydrageas, i'm not sure i could choose between them!
I ALSO LOVE WILD FLOWERS SO SO MUCH, i just think they're so delicate and dainty and pretty. i don't even think i could name some of my favourite ones but i absolutely love one called queen of the meadow!
I've never really paid much attention to proper flowers that are popular with most people, so I'd have to give it some more thought. That said, three that readily come to mind are the rafflesia, wolfsbane, and Venus flytraps.
I've thought rafflesia were neat since I first saw and learned about them in a book when I was a kid, and the fact that the Pok?mon Vileplume is based off of the rafflesia gives it some extra cool points as far as I'm concerned. I'm also one of those people who would want a rafflesia in their New Leaf town if you didn't have to have a terrible town with no Public Works Projects, but alas.
I don't really know much about wolfsbane other than that it's purple and poisonous, but I like it because of this poem from the 1941 film The Wolf Man:
"Even a man who is pure in heart, and says his prayers by night;
May become a wolf when the wolfbane blooms and the autumn moon is bright."
Meanwhile, while Venus flytraps probably don't seem applicable at first glance, they do in fact grow flowers so I figured I'd include them. They're just neat.