There's a list as long as your arm... First rule though, don't buy any plant with double flowers (for example, dahlias - buy the open, daisy type ones, not the fancy, spiky ones). Also avoid F1 bedding, which is most of your summer bedding such as busy lizzies, bedding begonias, although Lobelia they do like.
That said, Monarda, Scabious, Lavender, Hebe, purple or blue forms of Salvias, Foxgloves, Campanulas, Malva moschata, Calendula, Eryngium, Echinacea, Verbena bonariensis or rigida or hastata, Echinops ritro, Buddleia, Chives, Oregano, Thyme (if you let them flower), Cosmos, Hesperis. I'm sure people will come up with others as well. All these are more effective for bees and butterflies if in sun.

Thank you. I have buddleias, thistles, hebes and echinacea just need to get some more. Don't seem to have much out now in the garden.

Here's one that's coming into flower now, and the bees love it - Pulmonaria. Mine was literally buzzing downstairs with all the visitors.

According to Sarah Raven, any of the Centaureas. I've planted lots this year. Another honey-pot for bees is Marjoram and it's a lovely herb. My Verbena bonariensis attracts Hummingbird Hawk Moths - fascinating.

When anybody asks this I always add golden marjoram. It has lovely lilac flowers all summer, pretty golden leaves all year round and is full of bees and hoverflies for months on end, more than any other plant in the garden. Its easy going, low growing, spreads into a large clump but is not invasive.

Thank you

The bees seemed to love my sunflowers last year, also my friend has a massive lavendar and they adore it.

thank you

I'm a big fan of golden marjoram. As Stereagram says the insects love it

'lavender' XD

Thank you everyone will try these. I have tried to grow lavender before but it seems to die after the first year.