For a few years I have been opposed to LED lamps, on the grounds that they were overpriced and no more energy-efficient than CFLs (the older type of energy-saving lamp).
I am pleased to say that prices have at last dropped, and the next generation of lamps is now on the market with noticeably improved efficiency.
Last month Tesco were trying to sell ordinary Osram LED lamps for £10; they have now dropped to £5.
I have recently been buying Philips and own-brand lamps for about £3 at Wickes, and yesterday I collected an order of small spots from Wilkinsons at £2 each. They use about half the electricity of my old CFLs.
At the time of writing there seems to be a shortage of lamps of the same brightness as the old 100W incandescent lamp, which should have an output of about 1400 lumens, and in the new generation should use less than 20W of electricity. I expect they will be along soon. Being small and bright they are more inclined to cause glare, so consider lamps with a golfball or pear-shaped opal shroud to simulate the appearance of incandescent lamps.
BTW the manufacturers are at last prominently making light output, in lumens, on the packaging, so you know how bright they are. Although Philips are still using an outdated and incorrect method.
Hooray!