Hi Bowdeeka, I'm doing the same thing this year. I know it's not a classic garden plant, but I'm going to try bird's foot trefoil in hanging baskets - I think it will look lovely. It's a favourite nectar and pollen plant with bees, and some species of butterfly breed on it. You could also try phacelia, which is more often used as a green manure. The flowers are gorgeous and will flop over the side of the hanging baskets beautifully, and are also incredibly popular with bees. You won't be able to find these plants at garden centres though, you'll probably have to grow them from seed. I've had a quick look on Google and phacelia seeds are available from a few companies, both as a green manure and a cottage garden annual. Bird's foot trefoil seeds are available from wildflower seed merchants, though you may have some growing in your lawn!
More traditional plants to try include nepeta, cranesbill geranium, salvia. If you have these plants growing in your garden you could just divide them and plant small chunks in the hanging basket.
Hope this helps
Kate
gardenersworld.com team