Well I'll be the first, difficult to choose, but here's a few:
Spiraea 'Goldflame'; Pieris 'forest flame'; Nandina domestica 'Firepower'; Hakonlechloa 'aurea'(a grass); Berberis 'bagatelle' and an evergreen, very ordinary perennial - Campanula muralis. As for a tree, I guess Acer 'flamingo' and Laburnum. All low to no maintenance, just how I like it!

I grow hardy geraniums, and they're wonderful plants. I wouldn't be without them! I could go on and on about what else I grow - but maybe I'll just mention Clematis - I have one in flower every month of the year. :-)

Ooh, I forgot one - top of the list, Cotinus coggrygia Royal Purple, love it, but it gets very large.

In terms of plants all of these are superb value for money

http://www.growsonyou.com/anchorman/blog/12681-plants-with-a-very-long-flowering-season

Here, with acid soil, Camellias! They flower from December to May with no attention at all. And hardy Fuchsias, and hardy geraniums as Spritz says.

Can't beat Pyracantha- a really good, year round interest plant. Lavender is also another favourite of mine.

thank you all for these considered responses, most appreciated. I do have some Pieris in one of the borders and actually have a few different varieties of lavender in a poor soil border too..these are yet to spread and cover the area and the weeds are still prominant until i work them out. Never come across bamboo's suggestion of Cotinus coggrygia Royal Purple before but like the look of this so will try it..

thanks all again

Heleniums.....long flowering season.....easy to split and move....grow on well after moving......lovely bright, warm colours.....not many pests. Agree about camellias too and some hardy geraniums.

Heleniums get eaten in my garden - I think it's snails/ slugs.

I like the variegated Euonymus 'emerald gaiety' and 'emerald n gold' they are colourful all year round , bone hardy and provide a backdrop to so many other plants and flowers
and welcome to Goy-- check out the blogs theres a wealth of interest there....

skimmia is a favourite of mine as is escallonia. as for perenials oriental poppy, lupins, delphiniums, heleniums, japanese anemones. annuals nigella allowed to self sow year on year.

Agree with Bamboo about Cotinus - lovely purple leaves , makes a great backdrop and virtually no maintenance; Nandina domestica is also very easy (evergreen with pretty red on leaves). I love Amelanchier as a small tree: white blossom in April and autumn leaf colour. Viburnum mariesii is an attractive shape, with long-flowering white flowers. Alchemilla mollis for a perennial - plant with anything purple. Oh, and 2 grasses which are beautiful . . . Stipa tenuissima and Anemanthele lessoniana (used to be called Stipa arundinacea)! Good luck and have fun.

Fascinating answers ....
I could think of lots, but aubrieta, euonymus and pieris come to mind immediately ...

Viburnum summer snowflake, small shrub, lovely white lacecap flowers for ages. I've had mine for years and it seems to need no attention. I agree with all the above suggestions. I have the cotinus, it's a lovely sight with the sun behind it and doesn't seem to mind hard pruning. I would also include I. golden king for all year round colour. despite its name, this is a female holly so if there are any males around, you also get the benefit of bright orange/red berries. You can also make it almost any shape you want. Heucheras need so little attention and there's one for most positions. All year round colour, most are happy in light shade/part shade and some take full sun. Many have fabulously coloured leaves and pretty dainty flowers. For easy, knock your eyes out beauty, what about lilies? I find them very easy going. :-)

thank you bornagain..another great set of suggestions..i will check these ideas out

thanks

A bit late in the day I'm afraid as I have only just seen your blog, and much depends on how you define beauty! but a couple of suggestions from me would be Buddleia Black Knight - a gorgeous deep blue/purple colour - to attract butterflies and bees; Osmanthus Burkwoodii for its lovely perfume (very hardy and it needs little pruning); and an English rose which is highly scented e.g. Gertrude Jekyll, Brother Cadfael (both David Austin roses). If you can wait for it to grow you could try Enkianthus Campanulatus for its stunning autumn colour. Oh and maybe a Deutza Scabra 'Plena'; a lovely shrub with arching branches and delicate flowers.