If there is was family of plants that I couldn't be without it is the Geranium family. I have many varieties in the garden, and year by year I collect different varieties, mainly because they need little attention, are not prone to slug damage and their simple flowers blend in well with my desire for a natural-looking garden.
The scent-leaved ones I use as house plants during the winter, as they are not frost-hardy, but put them out in containers during the summer. The Pelargoniums, which include Zonal (plants with rounded leaves distincively marked with a darker zone and single or semi-double flowers) Regal - shrubby plants with rounded to overly deeply serrated leaves and broadly trumpet shaped exotic coloured flowers and Ivy leaf (trailing plants ideal for hanging baskets).
Scent-leaf Geranium (lemon fizz)
The other half of the equation are the perennial Geraniums (Cranesbill) - these are many and varied and are grown in the borders, rather than in containers and baskets. There are plenty of different varieties in the garden centres and I have at least nine different types but I try to increase my stock every year with different colours from white through different shades of pink to purple. They seed themselves about quite freely and are easy to split each autumn or spring. They thrive in shade or full sun as far as I can see and after they have flowered I give them a good chop back and usually they thank me by giving a second showing of flowers. As I have said before - I just couldn't do without them.