What are the best flowere to attract butterflies?

Any flower that produces nectar attracts butterflies. Most flowers produce nectar.

I'm not sure about flowers but I have read that over ripe bananas split open work really well.

I love flowers and butterflies. I dont know which flowers attract them but i would think the ones that give off the smell they like (its a shot in the dark lol) but i will look back in to see if you get an answer i would like to know also.

i have heard of butterfly bushes, i am not sure what flowers are on them but that is what they are called and they attract butterflies

You already were given my first answer and it is a very good link

there is another that has kits with the seeds in them and I believe its   www.butterflygarden.com

I dont think there are any particular flowers that attract butterflies more as compared to others. I love butterflies and it has been a personal experience that the more variety of flowers you have the more butterflies are attracted to them. A personal preference is of bright cloured flowers with a high scent.

This site looks like it has really good info on making a butterfly garden. Even classifies everything by state. I've wanted to one for awhile, I love butterflies. I remember when I lived in Kansas, must've been the migratory time for monarchs, all you could see around were these monarch butterflies. It was so cool, but it also sucked because we were driving and they were smashing into the windshield lol. There must've been hundreds of thousands maybe millions just fluttering around. It was neat!!

I used to grow potted heliconia and orchids in my apartment porch and there wasn't a single butterfly to be seen. Eversince I changed the plants to bougainvilla, I've seen many butterflies flying 4 storey high to 'patronise' the clusters of flowers of my plants. So I believe butterflies love bougainvilla.